The part is mounted, instead of the solenoid cover, with three screws on the starter and complety replaces the electrical starter circuit. Moving the lever to the right (in the direction of travel!) causes the starter pinion to engage in the starter clutch and closes the contact for the starter motor. A spring on the lever prevents it from becoming loose.

Fits Big Twins and Sportsters, but may need to be relocated or modified depending on exhaust system.