Grade 25 ball bearings for everyday repairsGrade 25 refers to the roundness where these bearings can be up to 25/1000 out of round; 1200%higher quality than low-end bearingsThis bearing is available only in grade 300 for use with BMX bottom brackets and other similar placesMade from high quality, heat treated steelComes in a recycled plastic bottle for use in the workshop so spare bearings won't get lost or soiled