Ceramic hybrid combines the chromium steel races found in enduro39s abec 5 range with grade 5 ceramic 40silicon nitride si3n441 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 bearing code mr 18307 dimensions 18mm x 30mm x 7mm abec 5 grade