This part is an engine pulley that is used on lawnmowers and lawn tractors. This engine pulley is often referred to as a serpentine belt. This belt aids in powering peripheral devices within the engine compartment, such as power steering.A new engine pulley may be needed if the belt is broken or torn upon a quick visual inspection. The operator may notice that there are squealing sounds coming from the lawnmower or lawn tractor if the pulley is beginning the fail. Remember to wear gloves when operating or performing care and maintenance on any outdoor power equipment. Never perform care and maintenance on outdoor power equipment that is powered on.This engine pulley is a genuine MTD part. It is sold individually. This particular engine pulley is compatible with lawnmowers and lawn tractors that are manufactured by MTD, Yard-Man, Cub Cadet, Husky, and Yard Machines.