VP Components – BC-73 Square Taper Bottom BracketThe work horse bottom bracketFeatures:Sealed cartridge bearingsBoron steel spindlePhosphated cupsAnODIzed aluminum sheathThread spec: BC1.37 x 24T280 gramsJIS taper (fits modern cranks- not compatible with classic European cranks)Available in the following sizes: 68mm shell by: 107mm, 110.5mm, 113mm, 118mm, 122.5mm, 127.5mm73mm shell by: 110.5mm, 113mm, 118mm, 122.5mmGreat replacement for the Shimano BB-UN54 or BB-UN55