This Bottom Bracket is when you have a PF30 shell frame and want to install a BB30 crankset into the frame. All have a 46mm inner diameter and smooth insides, to a frame width of 68mm and a total of 86mm with the BB installed. This BB is for a 30mm spindle .

This bottom bracket features nearly zero loss of power due to friction, thanks to the bearings. The bearings have super round, super smooth CeramicSpeed balls rolling on hardened-steel races. The Coated version has a metallic coating laid onto the races, making them even harder and smoother, resulting in longer life and lower drag. They come installed in cups.