Most of the interlock kits use zip ties to lock the generator breaker in place. This one uses a bracket just like the manufacturer available one does. Electrical inspector oked this one. Had one of the others turned down.

I like that it came with the drill bit you need for installation

Well-made and straight forward installation. A quick YouTube tutorial, power drill and installed pretty quick.

If you are going to use a portable generator for house power when utility service is out due to weather or other reasons, you must disconnect your house from the mains when the generator is operating. If you don’t, you risk backfeeding generator power onto the grid which can be very dangerous to utility workers. For this reason, in most places an interlock is required by code and it may even be illegal (i.e. a crime) to connect a generator to your house without one. An interlock is simply a mechanical device that makes it impossible to feed generator power to the service entrance panel (circuit breaker panel) if the main breaker is in the “on” position. Either the main breaker is on or the generator breaker is on, but both cannot be in the on position at the same time due to the presence of the interlock.At the time of this review, the seller offers two versions of this interlock kit – one for breakers that are 1.5 inches tall and one for breakers 2 inches wide (both measured vertically facing the breaker panel). The 1.5 inch model is for Square D “QO” style breaker panels and the 2 inch is for the Square D Homeline series breaker panels. They are NOT interchangeable so make sure you get the right kit for your style of panel.If you have a Square D (Schneider Electric) “QO” style service panel, the 1.5 inch version of this interlock kit is perfect for you. It is identical to and a direct substitute for the OEM kit (Schneider part QOCGK2C). Side by side on the bench, I could not tell the difference. When installed, I could not tell the difference. The fit and function was spot on. And at less than one-third the price of what I could get locally at the Orange, Blue, or Green big box home improvement stores, it fit my budget as well.Comes with all the parts you need (except for the generator breaker) for the installation. You even get a drill bit for drilling the panel cover for the mounting screws.I used this kit (1.5 inch version) on a Square D model QO140M200 panel (200 amp main breaker / 40 circuits) with a QOC40US cover. Both original to the house circa 2005. For the generator breaker, I used a 2 pole/30 amp QO230 (ASIN: B00002N5IH) as that is what my generator is rated for. My panel happens to be installed with the main breaker at the bottom (bottom feed installation) and this interlock kit worked just the same as if it had been a conventional top feed arrangement. Keep in mind that the generator feed breaker MUST be installed in the first two slots (breaker #2 and #4) for this kit to function. Therefore, if those slots are already in use by other circuits you may need to move some existing breakers as part of the install. If your panel is mounted in the typical main on top position, #2 and #4 are the top breakers on the right side. If it is upside down like mine, they are the bottom two breakers on the left. Your cover should be stamped with numbers next to each slot so identification should not be an issue.Now, although this kit includes instructions, requires only minimal DIY skills, and needs only common tools to complete the install it does require work inside your service entrance panel. BE CAREFUL. Even with the main breaker off, there is still power coming into the panel. If you don’t know what you are doing, or are afraid of electricity, STOP. Find or hire someone who does know what they are doing to do the work. Saving a few bucks is not worth losing your life to electrocution.I would not hesitate to use this interlock kit again versus the much overpriced OEM kit and would not have reservations about recommending it to a friend or family member if they had a need for it. As it does what it is supposed to do, has quality and functionality on par with the OEM part it substitutes for, and is a great value I have no qualms about rating it a full five stars.DISCLAIMER: I am a member of the Amazon Vine program. This means that I receive some products free of charge (but considered income to me for tax purposes) to use and review. I only request/accept items I will actually use. My reviews are based on this real-world usage – they are not mere regurgitations of the Amazon product description or insincere hype. I am not a shill and I do not consider the fact that an item was provided without charge as part of my ratings. I have given Vine products one star, five stars, and all points in between. A defective, incomplete, dangerous, or fraudulently described item gets 1 star (zero is not an option), a below average product 2, and an average product 3. You have to earn a 4 or 5 star rating. I put serious effort into my reviews and they represent my honest, hands-on opinion of the product. My hope it they will help you make an informed, educated choice whether or not a product is right for your needs.

Very similar to OEM kit at a fraction of the price. I have installed both OEM and this model. It would be hard to tell the difference between the two. Will purchase again when needed and recommend.

I have a Square D 200 amp panel in my house. It uses the Homeline breakers. I am installing a gasoline generator emergency feed. The generator power will enter the 200 amp panel at a 30 amp 220v double breaker. An interlock is required, so the QYZZRS was selected and installed. I am a pretty fussy DIY guy, so I always look for things that just don't fit right or are sloppy and/or awkward. I am pleased to report that this QYZZRS interlock kit is a slam dunk for accuracy and easy install. I expected the supplied drilling template to be a little sloppy and move around....wrong! The "location tab" formed into one edge slips into the breaker knock-out hole like a precision machined fit. This makes it a cake walk to hold the template with one hand and run a 3/32" drill bit thru the template holes with the drill in the other hand (I used my own 3/32" drill bit because it fits perfectly inside the template holes). This creates 3 pilot holes that can be enlarged to final dimension with the kit-supplied drill bit (and even the kit-supplied drill bit is super sharp and HSS hard, easily cutting thru the pilot holes I created). The nuts on back side that secure the shoulder bolts are 8mm. Crank 'em down, and the final product is clean, stable, and looks like a pro job.

I’ve been going to put a generator inlet plug in my panel for some time, and I finally got around to doing it. I needed a manual interlock kit, when I found this one. It works exactly as it should. It seems to be made of quality materials, and was super easy to install. If you have any mechanical aptitude at all, this is a pretty easy one to tackle. One thing to remember when ordering one of these, is to make sure it’s for your brand of panel, and that you have the correct amperage rating of the main breaker. It wont fit right if you dot have this information. I would recommend this interlock.

I included photos of this installed. My breaker box is a square D and was present when I bought my home. It’s a standard outside box.I am no electrician, and yet this was extremely simple to install. It doesn’t require any electrical expertise to take the front plate off of your breaker box. It was only 3 large screws. To install this, you simply take that front plate off of your box, and drill holes using the included template, which you hold up against the correct area of the back of the plate. You could also first mark the front of the plate by holding the interlock kit in the correct place, which is what I did.Installation is literally just pulling of the front plate and drilling 3 holes. After this, you attach the interlock kit, and then re-attach the front face of your breaker box. The interlock kit prevents both your generator breaker and main breaker from being “on” simultaneously. Pictures are indicative of the product.This product works and looks exactly as indicated in listing.