Front Rear Brake Disc Rotors for Yamaha XT660X Supermoto 2004-and upFit for Yamaha XT 660 X Supermoto 2004 and up Front floating disc This brake disc rotor is constructed from 420 stainless steel & anodized 6061 T6 aluminum. Wave shape brake disc for weight saving and increased clean effect. The slotted rotor ensures water and dirt are dispersed quickly when braking. The grooves on the disc surface create a self ventilating system to make brake system cool down and also prevent mud and dirt from interfering with