With precision sealed bearings and cold-forged, aluminum CNC machined cups, the Box One™ Titanium Square Taper bottom brackets are the best option for young BMX racers and other users. It is a three-piece crank in search of performance gains and weight savings. They have hollow, custom titanium-nitride-coated titanium spindles and carbon fiber center seals, helping keep the weight down between 185 and 190 grams (well below that of other square taper bottom brackets on the market). Other features include cups that are anodized black with anodized gold inner seals and a JIS tapered spindle that comes in either 108 or 113 millimeters. Weight Limit: 115kg (253 lbs) with limitations as per Category 2 of EN 16054:2012 Standard