Contains everything you need to upgrade your worn out clutch plates and springs, frictions, steels, and clutch springs, all made from premium grade materials. The frictions and steels are made with exact OEM tolerances and specifications, and produce the same feel and wear resistance of OEM plates. Wiseco clutch springs are 8-10 percent stiffer than stock to ensure a positive clutch lockup every time. Clutch pack kits are an easy solution to worn or slipping clutch packs. Fits: Yamaha YZ450F 2007-2013, YFZ450R 2009-2013.