Variants included the M820, M820A1 and M820A2. The M820 Expansible Van truck has windows, heating and air conditioning systems, and uses outside electric power. The M820A1 Expansible Van truck does not have windows, nor air-conditioning system; but does have a heating system. The M820A2 Expansible Van truck has windows, hydraulic liftgate, heating, and airconditioning
The M820 variant Expansible Vans transport electronic base stations into the field. In the traveling position, van truck bodies are 17 feet long by 8 feet wide (5.2 meters long by 2.4 meters wide). When in the field, van sides are expanded to give a width of nearly 14 feet (4.3 meters). They may serve as communication stations or electronic repair stations. The vans are designed to carry up to 5,000 pounds (2,270 kilograms) of equipment into the field. The M820A2 expansible van is equipped with a hydraulic liftgate, which makes it the preferred vehicle to use when heavy, delicate electronic equipment has to be moved in or out of van.
A crane lowers an M-820 Truck, Van, 5 Ton 6x6, Expansible toward the pier as it is offloaded from the Military Sealift Command vehicle cargo ship Cape Diamond (T-AKR-5055) during exercise Reforger '91, 24 August 1991. Van trucks on the dock are M934 and possibly other models.