The Avian Disc Rotor is available in 2 sizes, 120mm and 140mm diameter, the two most popular sized rotors found in the BMX race world. Check with the frame manufacturer before ordering your rotor to ensure you have the correct size.
The Speedco Velox frames run a 120mm rotor, while the Velox Evo frames require a 140mm rotor.
The hub mount type for this disc rotor is a ISO 6 bolt, and the 6 torx screws are included with the disc. This bolt pattern is nearly universal across all BMX race hubs, except those using a centre-lock style mount.