1COMPATIBILITY: The generator interlock kit is exclusively compatible with for Horizontal Main Cutler Hammer CH 150 or 200 amp panels. The spacing between the main breaker and the generator breaker is 1 1/2 inches. 2ALUMINUM ALLOY MATERIAL: The interlock kit is made of corrosion resistant aluminum alloy and undergoes surface anodization treatment, providing better electrical insulation properties, ensuring safe electricity usage. 3HIGH HARDNESS DRILL BIT: The professional interlock kit provides a 3/16in drill bit made of sturdy steel, allowing for easy penetration through the breaker panel. It is easy to install without the need for additional control boxes or wiring. 4SAFE USAGE: The generator interlock kit enables safe power supply to your home during power outages using a portable generator, preventing the utility and generator power sources from being activated simultaneously. 5RELIABLE AND CONVENIENT: The interlock kit ensures a reliable and convenient transition between utility power and generator power, providing peace of mind during emergencies and ensuring smoothly operation of necessary electrical equipment. 2 x Interlocking Parts 3 x Nut 3 x Screw 1 x Drill Bit 2 x Sticker 2 x Cable Tie 1 x Manual