Designed to stop engine run-on when electrical master disconnect is turned off by stopping electrical feedback in malfunctioning or high amperage alternators. More and more racing sanctioning bodies are recommending that this type of device be used. Compliments Battery Disconnect switches such as Moroso Nos.74100, 74101, 74102, and 74106. Kit includes: Heavy Duty Solenoid rated at 225 amps, mounting hardware, wiring harness, and terminal.