LING'S SHOP 1Pc New 31.8mm MTB Bike Cycling Saddle Seat Post Clamp Quick Release QR Style Material: Aluminum Alloy Clamp size: 31.8mm/1.25'' (Approx.) Fit for: 27.2mm Seatpost This is a quick release style clamp, convenient and useful You can adjust the clamp on the way even without any other tools, make your cycling smoothly