Internally expanding design fits most frames, including those with Swiss threading and frames with damaged BB shells. Installation requires only a traditional-style BB spanner or a pin wrench. The BB shell does not require chamfering or facing and the unit is easily removed so the existing threads may be reused. Sealed cartridge bearings for long service life. JIS spindle taper. Due to the larger diameter BB shell, Italian threaded bottom brackets are not compatible. Boron steel hollow axle.