YCX New Ultralight 18g Full Carbon Road Bicycles Seatpost Clamp MTB Bike Seat Post Clamp MTB Seat Tube Parts 31.8/34.9mm Gloss/Matte Type:Carbon Road / MTB Bicycle Clamp Size:31.8mm/34.9mm Height:16mm Use:Road bicycles,Mountain Bikes Finish:Glossy/Matte