The Topeak External Bottom Bracket Tool is designed for the installation and removal of external bearing cups, its hardened steel design fits to a 1/2 drive ratchet making your job much easier and accurate than normal! A must have tool for all Workstations of budding riders. Topeak External Bottom Bracket Tool Features Hardened Steel/ Engineering Grade Plastic Includes crank preload adjuster for Shimano cranks Fits ½” drive ratchet 5.2x4cm (2pcs) 132.6g