This part is an idler pulley. The idler pulley applies tension to and guides the engine drive belt. A wrench set is needed to perform any repair involving the idler pulley part.The idler pulley can become worn over time with normal use. Wear to the pulley can cause the belt to slip. Signs that the idler pulley needs to be replaced include squealing noises coming from the equipment, the engine stalling, or overheating. The idler pulley is an essential component and it is important to replace this part if it becomes worn, broken, or damaged in any way.This part is a genuine MTD part and is an OEM part sourced directly from the manufacturer and it is sold individually. This idler pulley is compatible with lawn tractors and snowblowers manufactured by MTD, Yard Machines, Bolens, Yard-Man, Troy-Bilt, Cub Cadet, and Husky.