Spring Coil Suspension: -in spring coil and damper rubber the vibration while , the post comfort your experience, the shocks. force adjustable by tighten or loose the bottom screw. Suspension travel 50mm.Pay Attention to Diameter Buy. Wrong diameter will not to install.They can be used with adapters to convert diameters.Easy to install and durable in use.Constructed of ultra light and strong aluminum .Suit for most Fixed Gear bike ,Road Bike ,Mountain Bike , Universal Bikes,etc.It fit for riders weight 50kg / 110lbs to 180kg / 397lbsTypes of: suspension seatpost Used for: Mountain Bike,road bikecolor:Black: size: 30.4 x 350mmPackage Contents:1 x suspension seatpostOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.