Used together with Park Tool HCW-4, this guide ring holds your spanner securely in place so you can install the drive side of a Sugino 75 NJS bottom bracket or Sugino 75 Super Lap bottom bracket, without worrying about the spanner slipping off the cup and making you say bad words.

Can you install a Sugino 75 or Super Lap BB without it? Of course, but once you use it, you'll never want to not use it ever again!

Also compatible with Hatta R9400, Suntour Superbe and Dura Ace square taper NJS bottom brackets.