Name: bike seatpost clamp. Material: 7075-T6 Aluminium alloy. Color: Blue, black, red, green, orange, purple. Diameter: 31.8mm/34.9mm. Package includes: 1PC Bike seatpost clamp. Suitable bicycle type: mountain bike, road bike, 700C. CNC seat clamp is made of 7075-T6 Aluminium alloy material, CNC precision cutting, ultra-light, high quality, long service life. Convenient design, simple installation. 34.9mm clamp fit for 30.9/31.6mm seatpost. 31.8mm clamp fit for 27.2/28.6mm seatpost.