This T45 Bottom Bracket is compatible with Shimano and other 24mm diameter spindle cranks. It is also known as the ThreadFit82.5 and Colnago standard. The CeramicSpeed kit comes with 2 threaded cups, dust covers, a spacer tube, and all-round grease. The bearings are preinstalled and come in two versions: Standard and Coated. Both feature round CeramicSpeed Balls and hardened-steel races. The Coated Bearings have a 3-micron thick metallic layer that improves durability and reduces drag. The result is a smoother and longer-lasting performance.