Mezzanine racking main components layer board of cooling-plate a for rolling, can according to 50 mm step up and down from the free adjustment, for convenience in operation personnel access goods, mezzanine racking total height is normally 2 meters of less than, if use the equipment, mezzanine racking height can reach 3 m. Mezzanine racking can be used alone, also can free joining together into various arrangement.