Soldiers transporting howitzer in GMC amphibious truck (DUKW)

View of soldiers transporting a howitzer in GMC amphibious truck (DUKW). Label on back: "Another of the Army's secret technical developments is the amphibious truck which the War Department has just disclosed and which is now in actual service with the U.S. forces in the war zones. These 'ducks,' as they are appropriately called because they perform both on land and in the water, are now in volume production at the factories of General Motors Truck and Coach. In the picture above, a 105 mm. howitzer is being carried across a body of water during test operations. (Approved by the War Department, Bureau of Public Relations.)" Handwritten on back: "Amphibious vehicles."