Park's Lockring Wrench is for installing and removing the adjustable-cup lockring used on Dura-Ace and XTR bottom brackets that use a left-side lockring (it fits several other models and brands of lockrings, too). The Lockring Wrench is laser cut and engages 5 of the lockring's 6 notches for a precise, secure fit. The vinyl-coated handle offers a great grip, too.
Features and Information
The major diameter of this tool is nominally 46.5mm. The minor diameter (at the notches), is nominally 41mm.
I contacted Park Tool about which BBT I should use on the lock ring for an early 70's Campy Nuovo Record. They told me this one, the BBT-7. They said the fit isn't perfect, but its not enough off to justify a separate production line for this tool. My vintage Campy lock ring tool is on the road somewhere in North Florida after bouncing out years ago. Good luck!
Bottom LineYes, I would recommend this to a friend