Sprocket Rear Quick-Change type RK B6638-40 For 530 CHAIN Needs* RK E0035 PCD3 AdaptorRear Sprocket. Made from C45 High Carbon steel. The sprocket teeth are heat treated (induction hardening), increasing the wear resistance and surface hardness. This quick change RK steel sprocket MUST be fitted along with the RK E 0035 adaptor SKU 3421150A (see additional image) to be able to mount on to a Ducati Hub It then allows future easy gearing or rear sprocket changes without the need to remove the complete rear Ducati hub. Manufacturer Part