This is a Shimano SM-BBR60 Bottom Bracket Unit. Weighing in at 77g, the SM-BBR60 Ultegra Bottom Bracket is 14 grams lighter than the 6700 bottom bracket offering professional level technology for the everyday cyclist. Features: Reduced size for light weight 14g lighter and 50% less friction than BB6700 Available in either 68mm English or 70mm Italian versions Specifications: Frame Interface: BSA/English Threaded Spindle Interface: 24mm (Shimano Hollowtech II, FSA MegaExo, Surly OD, FSA MegaExo Light, RaceFace EXI) Bottom Bracket Shell ID: 1.37 Shell Width: 68mm Color: Black Weight: 77g (Manufacturer Claimed)