Hysenm 1 Pair Mountain Road Bike Aluminum CNC Quick Release Cycling Bicycle MTB Seat Saddle Post Clamp 6160 aluminum made alloy body together with titanium axle, rust and corrosion resistant; CNC processing ensuring its high quality and durability Great for most mountain bike, road bike, and foldable bike Quick-release and locking design, easy to install with perfect security 31.8mm, fits for 27.2mm and 28.6mm seat post; 34.9mm, fits for seat post from 30.4mm to 31.8mm Two sizes and four colors for choice, satisfying different needs of customers