Shimano Dura Ace 7710 NJS bottom bracket

This NJS approved & certified bottom bracket is specifically designed for use with Dura Ace 7710 track crank arms. Specifications • 68mm English threaded (1.370" x 24 tpi) • spindle: 109.5mm Octalink • sealed cartridge bearings • NJS approved • crank arm bolts & dust caps sold separately • requires Park Tool BBT-22 & any track lockring tool for installation & removal • weight: 230g