Assuming that the boxes are similar in size...looking at the box from the top ... it's a trapezoid with the long base against the trailer and is about 79 " there. The front edge against the tank covers is about 48'. Front to back is about 12". Depth varies...where it sets over the tongue it's about 18"+ deep and to the sides it's about 21-22" deep. Our 19 has the two 6 volt batteries centered over the tongue but there is adequate room for leveling blocks, jack pads, sewer hose support, white water hose, extension cord, and a tupper ware box for water filter, electrical plugs, gloves, etc. Don't know how I would live without it.