Amazon.com : Bike Seat Post Clamp 31.8mm Aluminum Alloy Seat Tube Clip Bicycle Quick Release Seatpost for Mountain Tube Bike, Black : Sports & Outdoors
Amazon.com : Bicycle Flip Seat Post Shock Absorber. Suspension Seatpost, 31.8mm/33.9mm , Lightweight Aluminum Shock Absorber Seatpost Suitable ForMountain Bikes and Road Bicycle ( Color : Black 33.9*500mm ) : Sports & Outdoors