Improves clutch performance, clutch life and heat dissipation. Used by all major factory teams and riders. Precision-machined from billet T6 aircraft quality-aluminum to aerospace tolerances, and hard coated for 5x the wear resistance to stock, with proper maintenance. Allows clutch assembly to spin more true creating less heat when clutch is disengaged. Helps eliminate clutch chatter when used with Hinson Clutch Components clutch basket and inner hub.