1、COMPATIBLE OBJECTS: The interlock kit is suitable for vertical 150 or 200 amp circuit breaker panels with a 3 1/4 to 4 inch spacing between the main circuit breaker and the nearest generator circuit breaker 2、DURABLE MATERIAL: The interlock kit is made of corrosion resistant aluminum alloy and has been anodized on the surface for better thermal and electrical insulation, so you can use electricity safely 3、SAFE TO USE: Generator lock kit safely provide feedback to your home during power outages via portable generators, preventing utility and generator power from turning on at the same time 4、HIGH HARDNESS BITS: Professional interlocking kits offer 3/16in bits, strong aluminum alloy that can easily pass through the circuit breaker panel. Easy to install without additional control boxes or wiring 5、WITH FITTINGS: Generator interlock kit equipped with screws, nuts, drill bit, stickers, easy for you to install and use, complete accessories guarantee convenient operation