Impartial tests show that the MB-6 meter box stands up easier under heavier loads than they would normally be subjected. Compressive Tests: Boxes withstood traffic of 26,550 pounds. Tested on a universal Tinius-Olsen testing machine by Law Engineering and Testing Company, Geotechnical and materials Engineers, PO Box 13215,1412 Plasters Ave., NE, Atlanta, Georgia 30324.