This Bottom Bracket is for when you have a frame with a PF30, BBright, or 386EVO shell and you want to install a BB30 crankset into the frame. They all have a 46mm inner diameter and a smooth bore, although the widths vary from 68mm to 86mm. The crankset has a 30mm diameter spindle. This bottom bracket offers almost zero power loss thanks to reduced friction, due to the bearings. The bearings have super round and super smooth CeramicSpeed balls that roll on hardened steel races. The Coated version has a metal coating applied to the races, making them even harder and smoother, resulting in greater durability and less resistance. They come pre-installed in the cups. In the box: 2 cups with bearings installed 2 x 1mm spacers 2 x 0.5mm spacers 2 O-ring dust covers Spacer tube Universal grease Decal