The Wolf Tooth Axle for 12mm Rear Thru Axle does more than just secure wheels. Developed by Wolf Tooth, the engineers knew that they wouldn’t be able to get away with any old factory replacement part, even if it was made in Minnesota to aerospace standards. The Wolf Tooth Axle for 12mm Rear Thru Axle uses a captive steel washer under the head to reduce friction on the dropout face. This protects your expensive frame, transfers more of the tightening torque to clamping load for a stiffer interface, and prevents the axle from sticking or galling when you want to remove it. Wolf Tooth Axle for 12mm Rear Thru Axle Features These are also a great replacement option for lost or damaged stock axles. Always apply a small amount of grease to the washer and threads when installing. Check out the Axle Caps for added protection and the Trainer Caps for those days on the trainer. Wolf Tooth Axle for 12mm Rear Thru Axle Compatibility 12mm Rear Thru Axle Axle length is compatible +/- 2mm