JINXIU Size - The seatpost clamp has an inner diameter of about 31.8mm and will fit bicycle frame tube seatposts with an outer diameter of 30.2mm-32.1mm. Material - This bicycle seat tube clamp is made of high-quality aluminum alloy with anodized surface, which is light weight, high hardness, anti-corrosion, anti-rust, sturdy and durable. Easy to install - The bicycle seatpost clamp has a quick release and fixing non-slip nut, very easy to install and use, no complicated steps or procedures, it is very convenient. Easy height adjustment - Quickly release the clamp, which makes it easy to adjust the seatpost height, and makes the seat height adapt to your height, which is very practical, safe and stable. Wide application - The seat post saddle clamp is suitable for all kinds of bicycles, such as road bikes, mountain bikes, childrens scooters with lift bars, folding bikes, crawler vehicles, etc. Quantity:2pcs Colour:Black and Blue