The Chamberlain Liftmaster Square Rail Idler Pulley is a replacement part designed specifically for Craftsman garage door openers. Made by the trusted brand LiftMaster, this pulley is compatible with both LiftMaster and Chamberlain models. Manufactured in Mexico, this square rail idler pulley comes as a single package, ensuring a perfect fit for your garage door opener system. Upgrade your garage with this quality pulley to maintain smooth and efficient operation.