This is a A-RBW1-316 W Hub PN: RBW1-316Main Description As Following : A-RBW1-316 W Hub P.N: RBW1-316 Dim A (1): 1-5/8"Dim B (2): 1-13/16"Dim C (3): 7/16"Dim D (4): 1"Bore: 1-3/16" roundKeyway: 1/4" X 1/8" Crossed From: WSH20019 , , 20020019 , , 20020019 , , 3016-0118 , , 673-S80021400 , , 673S80021400 , Found in Section & Models : Chains/ Sprockets/ Pulleys/ Hubs > Hubs, (Miscellaneous) (UNDEFINED): SEVERAL Associated Items : New Also This is An Aftermarket Product And : Dim A (1): 1-5/8" Dim B (2): 1-13/16" Dim C (3): 7/16" Dim D (4): 1" Bore: 1-3/16" round Keyway: 1/4" X 1/8"