This starter relay assembly is a genuine MTD part, sold individually. This starter relay assembly can be used as a replacement part in a lawn mower. The purpose of the starter relay assembly in a lawn mower is to serve as a circuit breaker, diverting battery power and starting the small engine of the appliance.The starter relay assembly might have to be replaced if it shows clear signs of damage within the standard lifespan of a lawn mower. Signs of damage to a starter relay assembly can include a lawn mower that will not start, a starter that remains powered on after the engine starts, or unusual clicking sounds, among other potential signs. If any of these signs of damage are attributable to a damaged starter relay assembly, the component should be removed and replaced by this genuine OEM replacement part before using the lawn mower again.This is a genuine OEM replacement part sourced directly from the manufacturer. It is sold individually. This starter relay assembly is compatible with the following outdoor appliance brands: MTD, Cub Cadet, and Yard Man.