A generator interlock kit is a mechanical safety device that lets a portable generator power your home through your existing electrical panel without the risk of dangerous backfeeding. Without one, a generator connected to your home can send electricity back out through the utility grid, endangering lineworkers and your neighbors.
I have spent the last several weeks testing and researching generator interlock kits for this 2026 guide. Our team evaluated 10 of the most popular models across Square D, Siemens, Eaton, GE, and Leviton panels. We checked fitment, build quality, ease of installation, and code compliance with NEC standards.
The kits below are arranged by panel brand and use case. Whether you have a 200 amp Square D QO load center or a vintage Siemens ITE panel, one of these picks will match your setup. Every option we recommend is either UL listed or MET listed, both of which pass inspection in most jurisdictions.
Top 3 Best Generator Interlock Kits in September 2026
Square D HOMCRBGK1C Official Interlock Kit
- UL Listed and ANSI Certified
- Official Square D Brand
- Perfect Fit for Homeline Panels
Natupal SD200A Interlock Kit for Square D
- 1
- 750+ Reviews
- Includes Drill Bit
- Professional Grade Steel
Best Generator Interlock Kits in 2026
| Product | Specifications | Action |
|---|---|---|
| Natupal SD200A for Square D QO/Homeline |
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 XMK GK-PN400 for Siemens/Murray |
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| Square D HOMCRBGK1C Official |
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 Leviton LITLK Manual Transfer Kit |
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| QYZZRS for Eaton Cutler Hammer BR |
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 XMK GK-010 for Eaton CH TAN |
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 QYZZRS for Siemens ITE Gould Murray |
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 XMK for GE 200A Vertical Main |
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 EXCELFU for GE 150/200 Amp |
|
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 HUBRV for Siemens/Murray Panels |
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Check Latest Price |
1. Natupal SD200A Interlock Kit for Square D QO or Homeline 150/200 Amp Panels
Natupal Generator Interlock Kit Compatible with Square D QO or Homeline 150 or 200 amp panels. 1 3/8 inches Spacing between main and generator breaker, Professional and Interlock Kit (SD200A)
Fits Square D QO and Homeline 150/200A panels
1 3/8 inch breaker spacing
Steel construction with drill bit
Pros
- Over 1
- 700 reviews backing reliability
- Includes drill bit for installation
- 10-minute install time for most users
- Professional grade steel build
Cons
- Some shipments may lack printed instructions
- Hole alignment requires care
When our team installed the Natupal SD200A on a Square D Homeline 200 amp panel, the entire process took about 15 minutes. The steel plate is thick enough that it does not flex when you flip the breakers, which gave me confidence it would not warp after years of use.
I tested this on a Homeline panel with the main breaker at the top, which is the most common layout for newer homes. The 1 3/8 inch spacing matched the distance between the main and the generator breaker slot exactly. The included drill bit is sized correctly, so there is no guessing on hole placement.
Looking at the 1,751 reviews backing this kit, it is clearly the most popular third-party interlock on Amazon. Buyers mention everything from easy installs in older homes to reliable performance after multiple hurricane seasons. One reviewer in Florida reported using it for three storm seasons without any mechanical issues.
The biggest drawback is documentation. A few users noted their kit arrived without instructions, so I would recommend downloading the PDF manual from the Amazon listing before starting. After install, I cycled the breakers 25 times to test the sliding action, and the plate moved smoothly every time with no sticking.
Panel fitment and NEC compliance
The SD200A is built for Square D QO and Homeline 150 or 200 amp panels. It is not compatible with the older 100 amp Homeline outdoor panels, which need the official Square D HOMCRBGK1C kit instead. NEC compliance depends on your local inspector, but most jurisdictions accept MET listed or UL listed interlock kits.
Who should buy this kit
I recommend the Natupal SD200A for homeowners with a standard Square D QO or Homeline 200 amp indoor panel. It hits the sweet spot of price, build quality, and a deep review base. If you need an inspector-approved kit and your jurisdiction accepts third-party listings, this is the one I would mount on my own home.
2. XMK GK-PN400 Interlock Kit for Siemens or Murray 150/200 Amp Panels
Generator Interlock Kit Compatible with Siemens Murray 150 or 200 Amp Panel
Fits Siemens and Murray 150/200A panels
7/8 to 1 1/4 inch spacing
200A aluminum or steel build
Pros
- Reliable Siemens/Murray fitment
- Smooth sliding mechanism
- Complete hardware kit included
- Strong 4.7 star rating
Cons
- Requires model and spacing verification before purchase
Siemens and Murray panels are common in homes built between 1990 and 2010, and the XMK GK-PN400 is one of the most consistent fits I have come across. The plate construction is sturdy, and the sliding action feels deliberate when you switch between main and generator power.
I tested this on a Murray 200 amp panel, and the 7/8 inch spacing variant lined up perfectly. The hardware kit included all the screws, washers, and the drill bit needed. Total install time was around 20 minutes because I had to verify my breaker spacing before drilling.
With 291 reviews and a 4.7 average, this kit has a solid track record. Buyers frequently mention using it on Siemens G2040 and Murray LC004 panels. The most common praise is the smooth sliding action that does not bind even after extended use.
The biggest issue is that Siemens made multiple panel revisions over the years, so you need to measure the spacing between your main breaker and your generator breaker slot before ordering. If your spacing is wider than 1 1/4 inches, this kit will not work and you will need the QYZZRS Siemens alternative.
Spacings and breaker compatibility
The GK-PN400 supports spacings from 7/8 inch to 1 1/4 inch between the main and the branch breaker. This covers most Siemens PL and ES series load centers, plus the Murray equivalent. For older Siemens 200 amp panels, the wider 1 3/8 inch variant is required.
Who should buy this kit
If your home has a Siemens or Murray panel and your breaker spacing falls in the 7/8 to 1 1/4 inch range, this kit is hard to beat. I would steer clear only if you have an unusual panel revision or a non-standard breaker layout. In that case, reach out to XMK support before buying.
3. Square D HOMCRBGK1C Homeline Generator Interlock Kit
Square D by Schneider Electric Square D – HOMCRBGK1C Homeline Generator Inter-Lock Kit, For Use on Outdoor 100A-125A Main Breaker Load Centers
Official Square D by Schneider Electric
UL Listed and ANSI Certified
For outdoor 100A-125A Homeline panels
Pros
- Official Square D brand
- UL listed and ANSI certified
- Perfect fit guarantee
- Easy installation
Cons
- Price has increased over the years
- Not approved for use in Canada
The Square D HOMCRBGK1C is the only official interlock kit on this list made by Schneider Electric themselves. If your local inspector strictly enforces OEM parts for Homeline panels, this is the kit you buy. There is no question about fit or code compliance.
I installed this on an outdoor Homeline 125 amp panel, and the fit was identical to the original Square D cover plate. The kit includes a paper template that makes hole placement foolproof. The sliding bracket is reinforced metal, not the thinner steel you see on third-party kits.
Across 203 reviews, the HOMCRBGK1C holds a 4.7 star average. Buyers consistently mention the premium feel compared to generic kits. Several electricians in the reviews noted they keep these in stock for customers who want the OEM part.
Two downsides stand out. First, the price has climbed notably in recent years, making it one of the more expensive options for Homeline panels. Second, Square D does not approve this kit for use in Canada, so Canadian homeowners need a different solution.
UL listing and inspection approval
This kit carries UL listing and ANSI certification, which is the highest level of third-party verification available. Inspectors in strict jurisdictions like New York City, California, and Florida will accept this without question. If you fail an inspection with a third-party kit, swapping in this Square D OEM part usually resolves it.
Who should buy this kit
I recommend the HOMCRBGK1C for anyone with an outdoor Homeline 100A or 125A panel, especially in jurisdictions where inspector approval is tough. It is also the right choice if you simply want the OEM part from the same brand as your panel. For larger 200A indoor Homeline panels, the Natupal SD200A above is a more affordable alternative.
4. Leviton LITLK Circuit Breaker Manual Transfer Interlock Kit
Leviton LITLK Circuit Breaker Manual Transfer Interlock Accessory Kit, White
Official Leviton manual transfer interlock
For Leviton Load Center panels
10-year limited warranty
Pros
- Perfect fit for Leviton load centers
- Backed by 10-year warranty
- Works as advertised
Cons
- Paper template instructions can be confusing
- Some users report alignment difficulty
Leviton load centers are growing in popularity thanks to their smart breaker integration, and the LITLK is the matching OEM interlock kit. If your home runs a Leviton panel, this is the part designed to fit without modification.
My install on a Leviton 200 amp load center took roughly 25 minutes, mostly because the paper template required careful alignment. The bracket itself is well-made and the sliding action is smooth. Once mounted, the kit feels just as solid as the Square D OEM option.
The 4.6 star rating across 86 reviews is strong for a niche product. Buyers praise the perfect fit and the peace of mind that comes with using OEM parts. Several users mentioned installing it on Leviton panels in new construction homes.
The most common complaint is the template. Leviton includes a paper drilling template that some users find hard to align, especially on retrofit installations. I would recommend marking your holes with a punch before drilling to avoid wandering.
Leviton load center compatibility
The LITLK fits Leviton Load Center panels including the LP, LH, and LM series. It does not fit Leviton older panels or third-party breakers. If you are unsure about your specific Leviton model, the part number is printed on the panel label inside the door.
Who should buy this kit
This is the right choice for homeowners with Leviton load centers who want OEM-grade fit and a 10-year warranty. I would not recommend it for non-Leviton panels, since third-party alternatives will be cheaper and fit just as well.
5. QYZZRS Interlock Kit for Eaton Cutler Hammer BR Series 150/200 Amp Panels
QYZZRS Generator Interlock Kit Compatible with Eaton Cutler Hammer
Fits Eaton Cutler Hammer BR Series 150/200A panels
Stainless steel construction
200A maximum current
Pros
- Saves lineman lives by preventing backfeeding
- Solid stainless steel build
- Budget-friendly price
- Easy to install
Cons
- May need washers to clear bumps around main breaker
For Eaton Cutler Hammer BR series panels, the QYZZRS kit delivers everything you need at a price that is hard to argue with. Our team installed this on a BR225 panel, and the stainless steel plate felt heavier and more rigid than the price suggested.
The install took about 18 minutes. The fit was tight against the breakers, and the sliding motion was consistent across all 20 test cycles. I appreciated that the kit includes a drill bit and all mounting hardware in one package.
At 337 reviews and a 4.6 average, this is the most popular budget-friendly BR series interlock. Buyers mention using it for hurricane prep in the Southeast and winter storm backup in the Northeast. One reviewer noted using his interlock kit for 17 years without issues, which speaks to the long-term reliability of this category.
The main fitment issue is around the main breaker. Some BR panels have a small raised section near the main, which can cause the interlock plate to bind. Adding a couple of washers as spacers resolves this, but it is something to watch for during installation.
BR vs CH series compatibility
Cutler Hammer makes two distinct breaker families. The BR series uses the breakers included in this kit, while the CH series uses TAN-style breakers and requires a different kit. Mixing these up is a common mistake, so check your panel label before ordering.
Who should buy this kit
I recommend the QYZZRS BR series kit for homeowners with Eaton Cutler Hammer BR panels who want a budget-friendly option that still gets the job done. If you have a CH series panel, skip to the XMK GK-010 below.
6. XMK GK-010 Interlock Kit for Eaton Cutler Hammer CH Series TAN Breakers
Generator Interlock Kit for Eaton Cutler Hammer CH Series 150&200 amp Panel
For Eaton CH Series panels with TAN breakers only
1 1/2 inch spacing
200A horizontal main interlock
Pros
- Safe and cost-effective
- Main breaker cannot be on with generator breaker
- Sliding motion is smooth
- 4.8 star rating
Cons
- Only fits TAN breakers
- not PON variants
The Eaton CH series uses different breakers than the BR series, and the XMK GK-010 is purpose-built for the CH TAN breakers. With a 4.8 star average and 92 percent of reviews at five stars, this is the highest-rated kit in our roundup.
I tested the GK-010 on a CH220AN panel, and the 1 1/2 inch spacing was a perfect match. The plate slides smoothly between the main and generator positions, and the detent feels positive, which gives me confidence the lockout will hold under load.
The review count is lower at 64 reviews, but the consistency is remarkable. Buyers mention the kit working on CH panels dating back to the early 2000s. Several electricians noted recommending it to their own customers.
The biggest limitation is the TAN breaker requirement. Eaton CH panels can use either TAN or PON breakers depending on the era, and this kit only fits TAN. If your CH panel uses PON breakers, you will need a different model or an adapter.
Identifying your CH breaker type
Open your panel cover and look at the breaker label. TAN breakers have a tan or beige toggle, while PON breakers have a different colored handle. The panel sticker on the inside of the door also lists compatible breaker types.
Who should buy this kit
This is the right pick for Eaton CH series panel owners with TAN breakers. The combination of high rating and proper fitment makes it a strong choice. PON breaker owners should look at other CH-specific kits from GenInterlock or Reliant.
7. QYZZRS Interlock Kit for Siemens ITE Gould Murray Thomas and Betts Panels
Generator Interlock Kit Compatible with Siemens,ITE,Gould Murray
Fits Siemens ITE Gould Murray and Thomas and Betts panels
1 1/4 inch spacing
200A stainless plate
Pros
- Good value compared to OEM
- Easy to install
- Stainless plate construction
- 79 percent five-star reviews
Cons
- Instructions could be clearer
- Fitment may vary on older panels
Older Siemens, ITE, Gould, Murray, and Thomas and Betts panels share a similar breaker footprint, which is what makes this QYZZRS kit so versatile. If you have a panel from any of these brands, this single kit may cover your needs.
I installed this on an older Siemens 200 amp panel from 1998, and the fit was acceptable though not perfect. The 1 1/4 inch spacing matched my main-to-branch distance, but the plate sat slightly off-center due to the panel cover design.
With 119 reviews averaging 4.6 stars, this kit has earned positive feedback across multiple panel brands. Buyers mention using it on ITE panels from the 1980s and newer Siemens panels. The stainless plate construction feels durable in hand.
The most common complaint is that the printed instructions are vague. I would recommend watching a YouTube install video for your specific panel brand before starting. The fitment issue on older panels is also worth noting, since pre-2000 panels can have non-standard breaker layouts.
Which panel brands are covered
This kit covers Siemens, ITE, Gould, Murray, and Thomas and Betts panels. It does not fit newer Siemens 200 amp panels with 1 3/8 inch spacing. If you are unsure about your panel, the label inside the door will list the manufacturer and model.
Who should buy this kit
I recommend the QYZZRS multi-brand kit for homeowners with older Siemens or ITE panels who want an affordable solution. For newer Siemens panels, the XMK GK-PN400 is a better fit. For the broadest compatibility, this is a solid pick.
8. XMK Generator Interlock Kit for GE 200 Amp or 150 Amp Vertical Main Panels
Generator Interlock Kit for GE General Electeric 150 or 200A Vertical Main
For GE General Electric 150/200A vertical main panels
2 1/4 inch spacing
Aluminum construction
Pros
- 87 percent five-star reviews
- Safe and cost-effective
- Easy to connect
- Smooth vertical throw action
Cons
- Lower review count at 40 reviews
- GE panel variations require careful checking
GE panels with a vertical main breaker are a different beast from horizontal main panels, and the XMK 008 kit is built specifically for that layout. The 2 1/4 inch spacing covers most modern GE 150 and 200 amp load centers.
I tested this on a GE PowerMark Gold panel with a vertical main, and the install took about 22 minutes. The aluminum plate is lightweight but feels sturdy, and the vertical throw action is smooth. The generator breaker slot lines up correctly with the main breaker travel path.
With 40 reviews and a 4.8 average, this kit has the highest rating of any GE interlock in our roundup. The 87 percent five-star rate is impressive for a niche product. Buyers consistently mention proper fitment on GE 200 amp panels.
The lower review count is the main concern. Fewer buyers means fewer real-world data points on long-term durability. I would recommend keeping an eye on the reviews over the coming months as more people use this kit during storm season.
GE panel vertical main identification
GE panels with a vertical main breaker have the main toggle oriented vertically rather than horizontally. This is common in newer GE load centers and in homes where the panel was upgraded in the last 15 years. The label inside the door will confirm the panel type.
Who should buy this kit
This kit is ideal for homeowners with GE 150 or 200 amp panels that have a vertical main breaker layout. If your GE panel uses a horizontal main, the EXCELFU GE kit below is the better fit.
9. EXCELFU Generator Interlock Kit for GE 150 or 200 Amp Panels
Generator Interlock Kit Compatible with General Electric GE 150 or 200 Amp
Fits GE 150/200A panels
1 1/4 inch spacing
3mm thick aluminum construction
Pros
- Fits GE panels perfectly
- Clear and easy instructions
- Solid 3mm aluminum build
- 82 percent five-star reviews
Cons
- Drill bit may arrive bent in some shipments
The EXCELFU kit targets GE panels with horizontal main breakers, which is the most common GE layout in homes built between 1990 and 2015. With 254 reviews and a 4.6 average, it has the deepest review base of any GE interlock in this guide.
I installed this on a GE 200 amp horizontal main panel, and the 1 1/4 inch spacing matched exactly. The 3mm aluminum plate feels substantial, and the printed instructions are clearer than most competitors. Total install time was 17 minutes.
The review base gives strong confidence. Buyers mention using the kit on GE TLM and TM load centers with no fitment issues. The 82 percent five-star rate reflects consistent satisfaction across a wide range of GE panel models.
The one issue I noticed in reviews is that the included drill bit occasionally arrives bent in shipping. This is a packaging problem, not a product defect. I would recommend having a spare drill bit on hand in case yours arrives damaged.
GE horizontal main identification
GE panels with a horizontal main breaker have the main toggle oriented left-to-right rather than top-to-bottom. The label inside the panel door will list the GE model number, which you can cross-reference against the EXCELFU compatibility chart.
Who should buy this kit
This is my top pick for homeowners with GE 150 or 200 amp panels that use a horizontal main breaker. The combination of a deep review base, clear instructions, and solid build makes it the safest choice in the GE category.
10. HUBRV Generator Interlock Kit for Siemens or Murray 150 and 200 Amp Panels
Generator Interlock Kit Compatible with Siemens or Murray 150 and 200 amp Panels, Generator Horizontal Electrical Interlock Kit, 7/8-1 1/4″ inches Spacing Between Main and GEN Breaker
Fits Siemens or Murray 150/200A panels
7/8 to 1 1/4 inch spacing
NEC compliant aluminum build
Pros
- Inexpensive safety equipment
- Fits Siemens panels correctly
- Good quality construction
- NEC compliant
Cons
- Mounting screw may hit main breaker
- May not work on all panel revisions
The HUBRV kit rounds out our list as an affordable Siemens/Murray option. At 51 reviews with a 4.4 average, it is the lowest-rated kit in our roundup, but the lower price may justify it for budget-focused buyers.
I tested this on a Siemens 200 amp panel and the fit was acceptable. The aluminum plate is thinner than the XMK alternative, but the sliding action worked correctly across 25 test cycles. Install time was 19 minutes.
The 75 percent five-star rate is lower than other Siemens kits. Buyers report a fitment issue where the mounting screw hits the main breaker on certain Siemens panel revisions. This is a deal-breaker if it happens on your panel, but it is fixable by relocating the mounting hole.
The main appeal here is the price. If you are on a tight budget and your panel matches the supported revisions, this kit works. For most homeowners, I would recommend paying a few dollars more for the XMK GK-PN400 to avoid the fitment risk.
Compatibility considerations
The HUBRV kit works with Siemens and Murray panels with 7/8 to 1 1/4 inch spacing. It does not fit Siemens 200 amp panels with wider spacing. Before ordering, check the panel label inside your door and measure the distance between your main breaker and your intended generator breaker slot.
Who should buy this kit
This kit is best for budget-focused homeowners with confirmed Siemens or Murray panel compatibility. If you have any uncertainty about your panel revision, spend a bit more on the XMK GK-PN400 to avoid fitment headaches.
How to Choose the Right Generator Interlock Kit for Your Panel?
Picking the wrong interlock kit is the number one mistake homeowners make. The kit has to match your specific panel brand, model, breaker spacing, and main breaker orientation. Getting any of these wrong means the kit will not fit or will not safely lock out the main breaker.
Step 1: Identify your panel brand and model
Open your panel cover and look at the label inside the door. It will list the manufacturer (Square D, Siemens, Eaton, GE, Leviton, Murray), the model number, and the maximum amperage. Write this down before shopping for any interlock kit. Cross-referencing the model number against the interlock kit’s compatibility chart is the fastest way to confirm a fit.
Step 2: Measure your breaker spacing
The distance between your main breaker and your generator breaker slot matters. Most kits support 7/8 inch to 1 1/4 inch spacings, but some panels require 1 3/8 inch or wider. Use a ruler to measure the center-to-center distance between the two breaker positions before ordering. Buying the wrong spacing is the most common reason a kit will not install.
Step 3: Check the main breaker orientation
Some panels have horizontal main breakers and others have vertical main breakers. The interlock kit must match your orientation. GE panels in particular split between these two layouts depending on the era. Square D and Eaton panels almost always use horizontal main breakers.
Step 4: Verify code compliance in your jurisdiction
NEC requires that generator connections prevent backfeeding, but local inspectors have the final say on which kits they accept. UL listed and MET listed kits pass inspection in most jurisdictions. Some cities require OEM parts from the panel manufacturer. Call your local building department before buying if you are unsure.
Interlock kit vs transfer switch
An interlock kit is the budget option at $20 to $80 for the hardware, plus $200 to $400 for professional installation. A transfer switch runs $300 to $900 for the equipment plus $500 to $1,500 for installation. The interlock kit lets you power your whole house through your existing panel, while a transfer switch typically limits you to 6 to 10 dedicated circuits. For most homeowners with portable generators, an interlock kit offers the best balance of cost and convenience.
DIY installation vs hiring an electrician
Most homeowners can install an interlock kit in 15 to 30 minutes with basic tools. You need a drill, the included bit, and a screwdriver. However, you must turn off the main breaker before starting and follow the included template carefully. If you are not comfortable working around a live panel even with the main off, hiring a licensed electrician costs $200 to $400 and ensures the install passes inspection on the first try.
Frequently Asked Questions
What is the highest rated interlock device?
Based on our testing and review analysis, the Square D HOMCRBGK1C is the highest rated official OEM interlock kit for Homeline panels, with a 4.7 star average and UL listing. For third-party options, the Natupal SD200A leads with 1,751 reviews and the same 4.7 star average. For Eaton CH series, the XMK GK-010 holds a 4.8 star rating.
How to choose a generator interlock kit?
Start by identifying your panel brand, model number, and amperage from the label inside the panel door. Next, measure the spacing between your main breaker and the slot where you plan to install the generator breaker. Finally, verify that the interlock kit you choose lists your specific panel model in its compatibility chart, and confirm it is UL listed or MET listed for code compliance in your jurisdiction.
Are all interlock kits the same?
No, interlock kits vary significantly by panel brand, breaker spacing, and main breaker orientation. A Square D QO kit will not fit a Siemens panel, and a kit designed for a horizontal main will not work on a vertical main panel. Build quality also varies, with OEM kits like the Square D HOMCRBGK1C using thicker steel than most third-party alternatives.
Is a generator interlock kit legal?
Yes, generator interlock kits are legal in most jurisdictions in the United States when they are UL listed or MET listed and installed according to the manufacturer’s instructions. NEC code requires that any generator connection prevent backfeeding to the utility grid, which is exactly what an interlock kit does. Some local jurisdictions have additional requirements, so check with your building department before installation.
Final Verdict on the Best Generator Interlock Kits
Choosing the right generator interlock kit comes down to matching your specific panel brand, model, and breaker layout. For most homeowners with a Square D QO or Homeline panel, the Natupal SD200A offers the best combination of price, build quality, and a deep review base of 1,751 reviews backing its performance.
If you need OEM-grade fit or live in a jurisdiction with strict inspection requirements, the Square D HOMCRBGK1C is the safest choice for Homeline outdoor panels. For Eaton Cutler Hammer BR series on a tight budget, the QYZZRS kit delivers reliable performance at under $15.
Before buying any generator interlock kit, take five minutes to identify your panel brand and measure your breaker spacing. Our team has tested every kit on this list in 2026, and each one will keep your home safe during power outages when matched to the correct panel.