Shimano Dura Ace lockring
Dura Ace lockrings are made of hardened steel, NJS stamped and are guaranteed to keep your cog right where you want it.
For use with 13t cogs or larger.
Not compatible with Campagnolo, Miche, Phil Wood, Mack or Mavic hubs.
• NJS stamped
• 1.29"x24 tpi left-hand English threads