Damping:Coil Spring , you can add seatpost thim(27.2~28.6/30.4/30.8/30.9/31.6/33.9) to fit different size MTB Mountain Bike
With adjustable head, convenient to install. Standard clamp with 2-Bolt Zero Offset head clamp safety
How to Choose the Size(3 choices):(1) Check the Original Seatpost Size Marked on the body ,choose the same size as the original one.(2) Measure the inside diameter of the frame tube(normally it is not accurate, considering Operator,measuring tool , Temperature,etc.,).(3) Inquire the bike frame seller to get the further information
