English-threaded bottom brackets are known as BSA; it comes from British Standard Cycle. English threading on MTBs means a 73mm wide, 34mm inside diameter shell with reverse threading on the drive side. Its the most common threaded standard employed today. This kit works with 24mm diameter spindle cranks, found on Shimano, FSA, Rotor, among others. The cups have CeramicSpeed bearings pressed in. The Coated Bearing has CeramicSpeed balls running on a 3-micron thick coating placed on top of hardened-steel races for greater durability and less friction.