The Boa Black Belly Ceramic Bearings are featuring ultra strong silicon nitride ceramic balls that will resist corrosion and shattering for a lifetime of usage. The bearing housing is made of a corrosion treated steel and features rubber seals to keep moisture and dirt out. Each bearing is filled with a nano ceramic grease that helps keep the bearings running at their optimum.
With inbuilt spacers and speed rings, you won’t have to worry about losing them ever again, or messing with alignment of your spacers.