carbon fiber seat post with 31.6*300/350/400mm with high quality and reasonable price carbon cycle seat post Products Specification: carbon fiber seat post with 31.6*300/350/400mm Type:carbon seatpostModel:GSP01weave:3k/UD/12KFinish:clear coatingSize: 31.6*300/350/400mmWeight:220g±6g we also supply carbon frame,carbon fork,carbon saddle,carbon handlebar and other bicycle parts.