Quick Release Seat Post Clamp – Alloy 28.6–34.9mm for Mountain & Road Bikes
• You can adjust the clamp on the way even without any other tools. - 31.8mm hollow seat tube clip use for 27.2mm/28.6mm seat tube. - 34.9mm hollow seat tube clip use for 30.4/30.8/30.9/ 31.6mm seat tube.