The Rally Pro comes equipped with an anodized aluminum bar for the strongest protection available. A Nylon composite material is injection-molded around the aluminum guard for increased protection and an indexed steel bar-end insert mounts solidly and will not allow guard to rotate in a crash. The mounting kit X-STRONG is for handlebar with diameter between 22 and 22 mm (0.866 - 1.102 inch) . To mount it have a look on MOUNTING INSTRUCTIONS. Sold in pairs. Comes with mount kits for PRO TAPE, MAGURA and TWIN WALL XSTRONG mounts.