Designed to be used with X-Type or EXI cranksets. Manufactured from high strength aluminum & featuring custom retainer bearings. FEATURES BB Cups are forged & CNC machined from 6066 aluminum. Tapering wall construction to minimize weight. Custom 6805 16 ball retainer bearing Bearings feature our custom triple wiper seal to better retain grease & keep contaminants out. Bearings are factory filled with Phil Wood waterproof grease — tested & proven to extend bearing life.