Dynamic Lug Mount Rotor Adapter for Asphalt Racing Hubs with “backside” mounts and GEN III Sprint Inboard Hubs. With a hub mount bolt circle of 5 x 4.875” and will mount any 8 lug, 7.18" snap ring rotor. Made from high strength aluminum alloy with a corrosion and wear resistant Type III hard anodize finish. Use 300-12561 Snap Ring and Wear Plate Kit to attach rotors.