ITEM NAME:RT56 6 Bolt Brake Disc M610 Mountain Bike Rotor SM-RT56 M6000 Bike Brake Rot_kz.Easier installation-new fastening plate construction for quick and easy installation For resin brake pads only. Material: 1CR13(brake rotors )+Zinc(screw ). Color:silver (brake rotors)+ black(screw). Typeï ¼Å¡ brake rotors.