The Edge-O-Dock leveler permanently attaches to the face of a dock. It is recommended for docks to be at least 48 in. high. When the trailer departs, the lip drops automatically behind the face of the bumpers. Concrete recess is not required. It comes complete with bumpers and installation instructions. The ramp width is 66 in. A steel dock edge, or approach ramp is required for proper installation. The Electric Hydraulic Edge-O-Dock is the easiest to operate. After the truck is backed against the dock, push and hold the control button. The leveler raises and the lip will extend. The unit comes complete with motor, pump, control box, cylinder, lines and oil. The truck must pull out for leveler to return to stored position.