Made of aluminum alloy material, good quality and wear-resistant. Lengthened arm design, lengthened arm feel, light and labor-saving. The seat tube clamp is thickened and widened, which is firm and wear-resistant, stabilizes the seat tube and prolongs the service life. Frame bayonet design: precise bayonet to prevent the seat tube from slipping off. 2mm hexagon socket screws to strengthen the fixed seat tube. Simple and detachable assembly design: high-strength nylon gasket, not brittle, wear-resistant and compressive, and does not scratch metal parts. Specification: Material: Aluminum Alloy Size Chart: 46x73.5mm/1.81x2.89inch, suitable for 39.8mm/1.57inch seat post. Package Includes: 1 Piece Folding Bike Seatpost Clamp Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping!