Fits 16 notch external bearing bottom bracket cups measuring 44mm diameter such as Shimano BB80, BB5700, XT BB70, BB51, & previous external bearing threaded cups. Also fits many external Threaded types for Campagnolo, Chris King, FSA Mega Exo, Hope, SRAM/ Truvativ GXP, Race Face X-type, Surly, Wheels, & others.