Gear and Sprocket Replacement Kit Includes: Gear and sprocket, worm gear, grease, motor shaft bearings, sprocket bearings Compatible with Chamberlain, Sears, Craftsman and LiftMaster 1/3 and 1/2 HP chain drive models Compatible with chain drive Chamberlain Sears Craftsman manufactured operators 1984-current Installation: Step-by-step instructions included, free tech support available. This OEM kit 041c4220a includes all of the 41A2827 Drive / Worm Gear kit, and is easier to install because you do not have to disassemble the output shaft assembly - the spur gear is already mounted on the new output shaft Our After-Sales Service: lf you are not positive that this is the correct item for you, please contact us through our store front page "Ask a question". If you are unhappy with it for any reason, reach us and we will sort things out for you Gear and Sprocket Replacement Kit for Liftmaster 41c4220a 41A2827, fits Chamberlain, Sears, Craftsman 1/3 and 1/2 HP Chain Drive Models (Chain Drive Gear and Sprocket Kit)