●SELECTION OF SEAT POST CLIP: The diameter of the seat post is usually 33.9mm, choose the same size as the seatpost clamp you used before. ①. For polished or brushed seat posts, choose a 40mm seatpost clamp. ②. For painted seat posts, choose a 41mm seatpost clamp. ●Ultra lightweight and durable: the quick release ring for bicycle seat posts is made of ultra-light aluminium alloy, which saves weight and does not deform or break. ●FOLDABLE BICYCLE SEAT POST CLAMP The colorful folding bike seat post clamp is compatible with Dahon Sp8. Specifications: 40 m/41 mm ●ERGONOMIC DESIGN The bike seat post clamp is ergonomic and more comfortable, provides more grip and locks the seat post for a safer ride ●EASY TO INSTALL This bike seatpost quick release or seat clamp is a bicycle accessory or bike replacement that can be replaced in minutes without the use of tools