Wolf Tooth Centerlock Rotor Lockrings External Spline secure centerlock rotors on centerlock hubs. They are compatible with 12mm, 15mm, and 20mm thru axles and QR. These are available in eight colors that match other Wolf Tooth anodized color accents for headsets, bolts, seatpost clamps, and more. Centerlock Rotor Lockrings External Spline are made with 7075-T6 aluminum and machined at Wolf Tooth in Minnesota, USA.