This is a screw jack for manual operational use that is highly efficient and has a self-lock function. * Standard Capacity: 10~300kN * It has been constructed with a high accuracy bevel gear and a trapezoidal-shaped screw axis. Can be self-locked at any position during a stroke * Long-life is maintained with the smooth movement by lubricating the reduction gear's mechanism section with grease * Low handle-turning speed for the required stroke operation.