Shimano bottom bracket tool TL-UN66 - for Octalink and square taper
The Shimano TL-UN66 is a tool for mounting and dismounting cartridge bottom brackets with 20-tooth gearing as seen on Octalink and square bottom brackets. It is not compatible with Hollowtech II bottom brackets. Use the TL-UN66 with a 32 mm open-ended wrench or 1/2" square ratchet.