It is a high-performance oil pressure spring suspension fork, fit for Ecotric Fat tire 20 36V(FAT20810), Fat tire 20 48V(FAT20S900), and Dolphin. The switch in the hydraulic spring system can let you adjust the comfortable air pressure value according to the weight and road conditions. The fork-shaped bridge design makes the outer tube more stable and sturdy, effectively preventing the shaped tube from dust. It has great wear resistance, lubrication, and rebound, which can greatly improve your riding experience in practice use!