Machined aluminum shell threads together for precise bearing alignment and frame fit, reducing bottom bracket creaking and premature bearing wear. Replaceable Enduro bearingsMade in the USAABEC-3 sealed bearingsGrade 10 chromium steel balls, 52100 High Carbon Chromium Alloy Races Spindle Interface Type: 386 EVO , RaceFace/Easton CINCHBB Shell Width (mm): 61 , 83Bottom Bracket Shell I.D.: 46BB/Frame Interface: PF30 , Specialized Carbon OSBBDefined Color: BlackWeight: 145