The GMC CCKW is a 2.5 tonne 6X6 U.S. Army cargo truck that saw service in World War II and the Korean War, often referred to as a "Deuce and a Half" or "Jimmy". The CCKW came in many variants, based on the open or closed cab, and Long Wheel Base (LWB 353) or Short Wheel Base (SWB 352).Initially, all versions were of closed cab design (having a metal roof and doors) with all steel cargo beds. But as the war progressed an open cab version was designed that had fixed 'half doors' and a canvas top/sides and the steel bed was replaced by a wooden one to conserve steel. The wood bed proved unsatisfactory and a 'composite' bed with steel sides and framing, but with wooden slats for the bed, was developed. Later on, the 'wood/steel' composite bed was replaced by an all steel composite bed.