This is a A-RBX1-116 X Hub PN: RBX1-116Main Description As Following : A-RBX1-116 X Hub P.N: RBX1-116 Dim A (1): 2"Dim B (2): 2-1/2"Dim C (3): 7/16"Dim D (4): 1"Bore: 1-1/16" roundKeyway: 1/4" X 1/8" Crossed From: WSH30011 , , WSH30017 , , 20030017 , , 3016-0129 , , 6713-58763 JOHN DAY , 673-S80031200 , , 673S80031200 , 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): 2" Dim B (2): 2-1/2" Dim C (3): 7/16" Dim D (4): 1" Bore: 1-1/16" round Keyway: 1/4" X 1/8"