Description: 【Fitment】: The inner diameter of the Bike Seat Post Clamp is 34.9mm, which is suitable for frames with seat tube sizes of 30.4, 30.8, and 31.6mm. 【Please Note】: The above Bicycle Seatpost Tube Clip adaptation parameters are only applicable to general aluminum alloy frames. Some steel frames, iron frames, carbon fiber frames, etc. will have different applicable seat tube clamp sizes due to different frame tube wall thicknesses. Tube clamp size measurement method: The outer diameter of the frame where the seat tube is installed or the seat tube size plus 2 times the frame tube wall thickness can be obtained. 【Premium Material】: The Seatpost Clamp is made of aluminum alloy material, which is reliable, lightweight and sturdy. 【Application】: The Seat Tube Clamp is suitable for Mountain Bike, Road Bike, Track Bike, Folding Bike, Casual Bike, etc. It is an ideal seat post accessory. 【Packing List】: Each package contains 1x Seat Tube Clip. Specification: Material: Aluminum alloy Size Chart: 4cmx4cmx3cm/1.57inchx1.57inchx1.18inch Package Includes: 1x Bike Seat Post Clamp Note: Please allow slightly errors 1-2cm differences due to manual measurement.