This sprocket has a 9.8mm offset (Offset is measured from the sprocket bolt mount surface to the center line of the teeth.) The inner diameter of the center hole is 2" Fits 1973-1999 Harley Big Twin Softail, Dyna, FXR, Touring & 1986-1999 Sportster Models using a 530 Chain. NOTE: This sprocket is made to bolt up to stock 1973-1999 Harley Big Twin Softail, Dyna, FXR, Touring & 1986-1999 Sportster rear wheels, however, the final fitment will be dependent upon many factors of your application, so please take measurements prior to making a purchase. We also offer 51 Tooth rear sprockets as well as full conversion kits with a front sprocket and chain. NOTE: Remember a larger rear sprocket means more torque (geared down) and a larger front sprocket means more top end (taller gearing). NOTE: Because of tight clearance when using stock muffler mount or stock passenger peg mounts do not use an O-ring chain because the additional width may cause chain to wear at these components on deceleration.