The Shimano BB-RS500 Bottom Bracket Cups is an Outboard Bottom bracket bearing cups for use with 2-piece cap-free design road chainsets. Minimal bearing interface gives superbly smooth rolling; this bottom bracket spare is easy to install. Available in British thread or Italian thread. Shimano BB-RS500 Bottom Bracket Cups Features Outboard Bottom bracket bearing cups for use with 2-piece cap-free design road chainsets Minimal bearing interface gives superbly smooth rolling Easy installation Italian thread British thread