Made with high-quality materials and designed to improve our on-bike performance, the CeramicSpeed OSPW Campagnolo 11s Mechanical/EPS features a 13-tooth/19-tooth OSPW, which provides 40% lower friction over an 11-tooth pulley wheel and fits up to a 32T cassette. This oversized pulley wheel system is compatible with all Campagnolo electronic rear derailleurs (EPS) and all rear derailleurs with a mounting sleeve.