The Shimano Disc Brake Adapter are the finest disc brake adapters available for MTB disc brakes. It is built with an extremely stiff aluminum construction, so riders will able to achieve the proper brake alignment and optimum function. This bicycle disc brake adapter is for mounting with a Post Mount caliper to a Post Mount fork or bike frame. FEATURES: Stiff aluminum construction Mounting ware included Compatible with post mount calipers to post mount front fork or bike frame (P/P) Size: +20mm (140-160mm, 160-180mm)