Pinhead's solid axle wheel locks replace factory hex nuts to provide wheel security and improved safety. Locknuts are supplied for wheels with M9 and M10 axles. All three standard axle sizes (M9, 3/8 x 26 tpi & M10) are available individually to fit all solid axle wheels. All parts are precision forged and chrome-plated for consistent function and long life. Locks are installed once, using a special coded key, and remain on the bike to lock the wheels to the axle. The same coded key is used to remove wheels for servicing.