"Permanently attaches to dock to create a ramp to trailer. Offers service range of 5in. up and 5in. down. Lip drops automatically behind bumper face when trailer departs. U.S.A. Product Type Dock leveler, Items Included Bumpers and hook, OSHA Approved Yes, Quick Stop System No, Operation Mechanical, ANSI Approved Yes, Material Type Steel, Capacity lbs. 20,000, Width in. 72. Edge-O-Dock dock leveler permanently attaches to the face of your dock, providing immediate use while saving valuable floor space Never get lost or stolen and they eliminate pinched fingers and toes Includes toe guards Built-in grease zerk fittings 18 in. high bumpers to service low trucks Service range 5 in. above to 5 in. below dock height High strength steel construction minimizes weight Adjustable torsion spring counterbalance mechanism Mechanical spring counterbalance Edge-O-Dock is operated by hooking the lip and lifting until the tip of the lip clears the bed of the trailer With an outward lifting motion the lip is extended and the dock leveler is lowered to the trailer When the trailer departs, the lip automatically retracts behind the bumper face Units comes complete with bumpers and hook"