Enjoy the benefits of ceramic bearings with the FSA BB30 Ceramic Bearing Set. Ceramic bearings are stronger than steel and spin faster due to their non-porous surface that makes them virtually frictionless. These bearings are compatible with BB30 bottom brackets. Features: Ceramic bearings roll smoother and last longer Compatible with BB30 bottom brackets Replaces 61806RS or 6806RS bearings Specifications: Outer Diameter: 42mm Inner Diameter: 30mm Thickness: 7mm Compatibility: BB30 Material: Ceramic