Syntace SuperLock 2 35mm Seat Clamp for 30.9 Post 7050 aluminum construction, shot-peened and anodized An extra-long, ergonomic lever with self-locking adjustment nut No-wear 1mm stainless steel cam pivot plate between clamp and lever Seatpost diameter specific wiper seal keeps grime from entering the frame (measure frame and seatpost before ordering)