Liftmaster Gear Kit 41C4220A Gear & Sprocket Assembly Direct Replacement Includes: Gear and Sprocket, Worm Gear, Grease, Motor Shaft Bearings, Sprocket Bearings,Instructions Compatible with CHAIN Drive Chamberlain Sears Craftsman Manufactured operators 1984-current Compatible with Chamberlain, Sears, Craftsman and LiftMaster 1/3 and 1/2 HP chain drive models Verified 100% Authentic OEM Liftmaster Product- New Production Dates. Easy DIY- Complete Assembly.