... operation is very simple, free the button, the ramp drop by gravity, the extended board is on ... 2. Though driving system, big cylinder lifts the ramp, to the top, small cylinder lifts the extended ... 3 movables boards on both side of the ramp for safty to avoid from hurting labors’ ... the surface board, better in safty.Stationary yard ramp parameters: SpecificationVertical travel (mm)Capacity (Kg)Power ...