Prevent damage to your motorcycles 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. 28% finer teeth spacing (compared to '01-'06 chain adjuster) for more accurate adjustments. Active Plate and Back Support Plate investment cast with 4130 Steel. Chain shoe machined from Nylon 66. Increases torque by 3.42 ft/lbs. Reduces primary noise. Help prevent damage to primary. Improves motor bottom end and inner primary race bearing durability. Made in the U.S.A..