T47 is a standard created by custom frame builders. It’s threaded has an inner diameter of 47mm and is 86mm wide. It has the design benefits of being oversized and wide but also the practical benefits of threads. The cups have CeramicSpeed bearings pressed in. There are two bearing options. The Standard Bearing has CeramicSpeed Balls and hardened-steel races. The Coated Bearing has the same balls running on a 3-micron thick coating placed on top of those hardened-steel races for greater durability and less friction still. This BB is compatible with 86mm frames and also compatible with TREK T47 85.5mm wide frames.