JOES T-Nut System and Rotor Flange improve your braking efficiency. Hardened T-Nuts self center in the rotor flange. The small amount of movement allows your rotor to grow and shrink through heat expansion. As the rotor heats and cools the T-Nuts prevent warping related to heat expansion resulting in a smooth and firm pedal throughout the race. Pads last longer and rotor life is improved. Better braking gets you deeper into the corners. Pack of 8.