CeramicSpeed BSA Threaded BB Gravel DUB Coated BlackSave watts and ride faster with guaranteed lowest friction, optimized power transfer, and longest product lifetime External BSA, English threaded bottom brackets featuring anodized aluminum cups Coated: metallic layer that covers bearing races making them 75% harder than steel. Even lower friction and highly resistant to corrosion Standard: low drag with hardened steel races and ceramic ball bearings Mountain versions for 73mm bottom bracket shells or