Floating Rotor Adapter for Asphalt Racing Hubs with “backside” mountsand GEN III Sprint Inboard Hubs. With a hub mount bolt circle of 5 x 4.875” and will mount any 8 x 7.00” bolt circle rotor. Made from high strength aluminum alloy with a corrosion and wear resistant Type III hard anodize finish.. Use 230-14845 Rotor Bolt and T-nut Kit to attach rotors.