Don't be fooled by the title, Enduro have been producing bearings since before the word "Enduro" became fashionable, there bearings are an industry leading design and they set the standard for all other bearing manufacturers to match. You may be more familiar with the ABEC standards from the worlds of skateboarding and roller blades but Enduro have tailored their bearings for the specific demands of cycling. The entry level industry standard of a bearing is ABEC 1 but Enduro do not produce any bearing which comes in at less than ABEC 3, this means that even if you choose an entry level Enduro bearing it is of better quality than another manufacturer's entry level bearing.These standard ABEC 3/5 bearings are designed for use within bottom brackets or hubs and give outstanding performance and longevity to your components. Item Specifications Grade 10 chromium steel balls. Kit includes all of the parts to change out the Shimano or Race Face outboard BB bearings. May fit some FSA bottom brackets, but double check the bearing measurements. Includes 2 bearings, 2 seal/shims, and instructions. Suggested to be used with the outboard BB Bearing Replacement Tool.