These bottom brackets are equipped with hand-built coated bearings specially developed for off-road performance that offer extreme durability and feature a unique design for SRAM DUB 28.99mm cranks. Coated bearings utilize the highest-quality CeramicSpeed ceramic balls, running on hardened-steel races with a 3-micron-thick metallic coating that makes the races corrosion-resistant, harder, and smoother, increasing service life and reducing friction. - This product has a unique design specifically for SRAM DUB 28.99mm cranks - Native fit frame interface and no plastic adapters or excess spacers - This design features a custom integrated dust cover for maximum durability In the box: - 2 CeramicSpeed Bearings - 2 dust covers - Plast sheet - 1 x 3mm spacer - 2 x 1mm spacers - 10ml syringe of CeramicSpeed Long Life Grease - Sticker sheet