Fine workmanship and perfect style.Easy to install and durable in use.Made of aluminum alloy, the metal strength is higher, durable and safe, so as to your riding.The can be adjusted by double and double tracks, and the of the cushion can be adjusted according to your own needs, so as to the riding comfort.Safety , the product marks the safety , which adds protection for your riding. Please do not lower than the marked range of the safety when installing.Name: Mountainous Road Bicycle TubeType: mountain bike postApplicable: mountain bike/bicycle accessoriesStyle: B: 30.9 X 400mmWeight: about 313gcolor:BlackMaterial:aluminum alloyPackage Contents:1 x tube1 x upper clamping piece1 x lower clamping piece2 x nuts2 x screwOnly the above package content, other 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.