This is a genuine replacement recoil spring that is designed to be used with select lawn and garden equipment engines. The recoil spring is part of the starter pulley assembly. When the starter rope is engaged, the pulley will then engage the recoil spring, which retracts to cause the spinning that helps power the engine. This spring is subject to constant use and can become stretched or even snap over time and with regular use.This genuine OEM recoil spring is manufactured by MTD and designed to exact standards. It can be used in models from MTD, as well as those from RYOBI, Troy-Bilt, Yard Man, Yard Machines, and Bolens. The recoil spring is made of durable metal and sold as an individual part. The rest of the starter components will need to be purchased separately if they need replaced. Always wear gloves when performing engine repairs and be careful when working on the starter system because the springs and pulleys can be under a lot of pressure. Allow the engine to cool completely and disconnect the power before getting started.