Brand: KS EXA Model: Speed UP hydro Material: aluminum alloy Length: 410mm Weight: about 684g Stroke: 100mm Caliber: 27.2/30.0/30.4/30.8/31.6/33.9mm Suitable for mountain bikes, road bikes, and folding bikes. It is made of high-strength aluminum alloy material, CNC processing, high hardness, fine workmanship; 100mm stroke, adjustable lifting height by handle, hydraulic structure can be locked at any position; sealing ring can be effective Protect the inside of the seat tube clean, waterproof and dustproof, and keep the lifting parts lubricated.