50B12 #50 Roller Chain Gear Sprocket 1″ Bore 1/4 Keyway 12 Tooth Gate Opener
Liftmaster 71-1550B18LGH Sprocket 18 Tooth 1″ Bore B Type 50B18T Garage Opener Sprocket for #50 chain12 tooth1″ bore with a 1/4″ keyway B Type
Liftmaster 71-1550B18LGH Sprocket 18 Tooth 1″ Bore B Type 50B18T Garage Opener Sprocket for #50 chain12 tooth1″ bore with a 1/4″ keyway B Type