1、Compatibility: Interlocking kit is compatible with horizontal mains 150 or 200amp load center circuit breaker panel boxes. Install indoor or outdoor generators. 2、Work Process: Interlocking kit prevents utility and generator power from turning on at the same time, avoiding the inconvenience that may result from unexpected power outages. Suitable for 1-1/4in spacing between main breaker and generator branch circuit breaker. 3、Easy to Install: The generator interlock kit is supplied with a 3/16 steel drill bit that easily fits through the breaker panel. Easy to install, mounts on the front of the circuit breaker panel, no additional control boxes or wiring required. 4、Aluminum Alloy Material: The interlock plate is made of thick aluminum alloy, beveled and oxidized for corrosion resistance and a smooth finish. 5、Safe to Use: Interlock kit is used to safely direct generator power to any circuit in your home while ensuring you have safe access to all household appliances. Item Type: Generator Interlock Kit Material: Aluminum Alloy, Steel 2 x Interlocking Plate 3 x Nut 3 x Screw 1 x Drill Bit 2 x Tie 2 x Sticker 1 x Instruction Manual