Enduro Ceramic Hybrid XD-15 Bottom Bracket BSA DUBFeature XD 15 15degree Angular Contact cartridge bearings pressed into precision machined aluminum cups that simply thread directly into the BB shell Feature deep groove raceways allowing for maximum sized Grade 3 Silicon Nitride ceramic balls for for increased contact area and improved performance and longevity Manufactured to the highest standards at the Enduro Bearings production facility in California, USA Combine corrosion proof, cryogenically