Colnago created the ThreadFit82.5, aka ThreadFit, to make their oversized bottom brackets more durable. The T4530 bb threads into those 45mm diameter, 82.5mm wide shells and allows you to install 30mm diameter spindle cranks into your Colnago.The cups have CeramicSpeed bearings pressed in, and then are threaded into the bb. 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, which makes them faster and more durable. In The Box 2 cups with bearings installed. 2 1mm spacers. 2 0.5mm spacers. 2 dust covers. O-ring. Spacer tube. All Round Grease. Sticker sheet.