CYCLINGKING Mountain Road Bike Bicycle Cycling 3K Full Carbon Fiber Seatpost Seat Posts 27.2/30.8/31.6x350mm/400mm Diamter: 27.2mm/30.8mm/31.6mm;Length: 350mm/400mm Weight: about 210g to 240g on average;Fits 7mm standard rails Material: 3K Full Carbon Fiber For Bike Type: Mountain/Road/Cyclocross Bike Ultra light,High-strong,Non-deformable,Corrosion resistant.One Year quality warantty!