Ceramic Hybrid combines the chromium steel races found in Enduro\'s ABEC 5 range with Grade 5 ceramic (Silicon Nitride - Si3n4) balls found in Zero Ceramic bearings. This combination creates a lighter, more efficient and more affordable ceramic bearing, perfect for use in hubs or bottom brackets. The low contact LLB seals provide protection from water or dirt ingress, but without causing any friction or drag.Key Features: Bearing Code: 6001,Dimensions: 12mm x 28mm x 8mm,ABEC: 5,Grade: 5,Seals: LLB,Grease: Kyodo Yushi PS-2,Application: Hubs, Bottom Brackets,Weight: 17.74g.