Park Tool Bottom Bracket Tool BBT7 (xtr & dura-ace) Park Tool lockring wrench for installing Shimano Dura-Ace 7700, XTR M950 and similar lockrings. Precision laser cut for an accurate fit. Engages five of the six notches for a precise & secure fit on the lockring. Features Park Tools' familiar vinyl coated handle for comfort during use. Note: Only fits the older XTR M950 & Dura-Ace 7700 carteidge bottom brackets. Newer models such as XTR M952 & Dura Ace 7703 use a different tool.