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 2-1/4" Fits MANY 2000+ Harley Sportster & Big Twin models using a 530 chain. NOTE: This sprocket is made to bolt up to many 2000+ Harley Sportster & Big Twin rear wheels, however, the final fitment will be dependent upon many factors of your application, so please take measurements prior to making a purchase. If your bike is stock, you still may need to double check the offset against the front sprocket. We also offer 48 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.