Disc brake rotor made from hardened, corrosion resistant steel. The total dimensions are 183mm OD, 74mm center hole and 4.5mm thick. Rotor has a 4 hole bolt pattern with a 8mm bolt hole. Mounting holes (from center hole to center hole) are 92mm across and 65mm side by side. This brake disc rotor is most commonly (but not exclusively) used for 400cc ATVs and UTVs from companies like Odes and Liangzi.