The BBT-59.3 is a precision CNC-machined aluminum tool for the installation and removal of select threaded bottom brackets with 16-notch tool fittings, including Shimano Ultegra BBR60 and Deore XT MT-800 bottom brackets. Manufactured in-house by Park Tool, anodized for easy identification and featuring a ratchet/torque wrench-compatible 3/8″ drive.