specification: 31.8/34.9mm (1.25/1.37in) material: aluminum alloy packaging: 1pc Seatpost Clamp colors: black, red, blue, gold net weight: 31.8mm (1.25in): 35.8g 34.9mm (1.37in): 37.3g product name: mountain bicycle quick release seat clip adaptation: 31.8mm (1.25in) suitable for seat rods with an outer product size: 31.8mm (1.25in): 48 * 13 * 64mm (1.89 * 0.51 * 2.52in) 34.9mm (1.37in): 52 * 13 * 66mm (2.05 * 0.51 * 2.60in) diameter of 27.2/28.6 (some dead flying 27.2 poles use 29.4mm (1.16in) seat pipe clamps, please confirm with "actual measurement") 34.9mm (1.37in) is suitable for 30 4/30.9/31.6 outer diameter seat rod Features: 1. Made of aluminum alloy material, lightweight, durable and rust-resistant,has a long service life. 2. Convenient design, simple installation. 3. Simple seatpost clamp, free from the cumbersome process.