Wolf Tooth Centerlock Rotor Lockrings have an internal spline to secure the center lock rotor to the center lock hub. This locking ring is compatible with 12mm thru axles and QRs. It also has a slim design and internal spline that allows you to attach your existing Wolf Tooth Centerlock Rotor Lockring - External Spline to any frame or fork with no clearance COMPATIBILITY: Compatible with 12mm thru axles and QR and can be installed using Wolf Tooth Pack Wrench and Cassette Lockring Insert which can be torque up to 40Nm. Tex-Spec Weight: 10.5g Material: 7075-T6 Aluminum, Stainless Steel Shim Washers Country of Manufacture: -United States.