With precision sealed bearings & cold-forged, aluminum CNC machined cups, The Box One Titanium Square Taper bottom brackets are the best option for young BMX racers & other users of three piece cranks in search of performance gains & weight savings. They have hollow, custom titanium-nitride coated titanium spindles & carbon fibre center seals, helping keep the weight down between 185 & 190 grams. Other features include cups that are anodized black with anodized gold inner seals, & a JIS tapered spindle that comes in either 108 or 113 millimetres.