The BB-RS501 bottom bracket features an enhanced seal construction to provide long-lasting performance and service life. For use with Italian threaded bottom bracket frames. Designed for a perfect fit with Hollowtech II 24mm crank spindles . Anodized aluminum cups are high strength and light weight. Item Specifications: Bottom Bracket Shell I.D.: 36, BB/Frame Interface: Italian, BB Shell Width (mm): 70, Weight: 93, Spindle Interface Type: Hollowtech II, Defined Color: Silver, keyword search: RS-500,