Prevents damage to your motorcycle's left side motor case bearings, inner primary bearings, clutch hub bearings and transmission output gear bearings. Manual chain tensioner allows you to set the chain to the proper 5/8"-7/8" (cold) freeplay and never have to worry about it being too tight. Increases torque by 3.42 ft./lbs. Reduces primary noise. Helps prevent damage to the primary. Improves motor bottom end and inner primary race bearing durability. Replacement shoe machined from Nylon 6, sold separately. Made in the U.S.A.