The Wolf Tooth Centrelock Rotor Lockring External Spline secures centerlock rotors on centerlock hubs. They are compatible with 12mm, 15mm, and 20mm thru axles and QR. These are available in eight colours that match other Wolf Tooth anodized colour accents for headsets, bolts, seatpost clamps, and more. Centerlock Rotor Lockrings are made with 7075-T6 aluminium and machined at Wolf Tooth in Minnesota, USA.Wolf Tooth Centerlock Rotor Lockring are 4mm thick with a 44mm outside diameter. Make sure you have enough clearance to the frame or fork.Wolf Tooth Centrelock Rotor Lockring External Spline Highlights-Compatible with 12mm, 15mm, and 20mm thru axles and QR40Nm Max TorqueCan be installed with Wolf Tooth Pack Wrench