This is a A-RBW1516 W Hub PN: RBW1516Main Description As Following : A-RBW1516 W Hub P.N: RBW1516 Dim A (1): 1-5/8"Dim B (2): 1-13/16"Dim C (3): 7/16"Dim D (4): 1"Bore: 15/16" roundKeyway: 1/4" X 1/8" Crossed From: WSH20015 , , 20020015 , , 20020015 , , 3016-0114 , , 6713-57663 JOHN DAY , 673-S80021000 , , 673S80021000 , 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: 15/16" round Keyway: 1/4" X 1/8"