• Breakfast Unit: canned entree veal (early version), canned chopped ham and eggs (all subsequent versions), biscuits, dextrose or malted milk tablets (early version), dried fruit bar, pre-mixed oatmeal cereal (late version), Halazone water purification tablets, a four-pack of cigarettes, Dentyne or Wrigley chewing gum, instant coffee, a packet of toilet paper tissues, and sugar (granulated, cubed, or compressed).

• Supper Unit: canned meat, consisting of cervelat sausage (early version), either pork luncheon meat with carrot or apple (first issue), beef and pork loaf (second issue); biscuits; a 2-ounce (57 g) D ration emergency chocolate bar (early version), Tropical bar, or (in temperate climates) commercial sweet chocolate bar (late version), a packet of toilet paper tissues; a four-pack of cigarettes, chewing gum, and a bouillon packet (cube or powder).

• Dinner Unit: canned entree pork luncheon meat (early version), canned processed American cheese, Swiss and American cheese, or bacon and cheese (cheese entree all subsequent versions), biscuits, 15 Dextrose or malted milk (diastatic malt) tablets (early) or five caramels (late), sugar (granulated, cubed, or compressed), salt packet, a four-pack of cigarettes and a matchbook, chewing gum, and a powdered beverage packet (lemon (c.1940), orange (c. 1943), or grape (c. 1945) flavor).

 

In total three meals provided 2,830 calories and 79 grams of protein depending upon components. As it was originally intended as an "assault" ration to be issued for short durations, the K-ration was designed to be used for a maximum of 15 meals. The K-ration was mass-produced by several major U.S. food production companies, including H. J. Heinz, Patten Food Products Company and The Cracker Jack Company.

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K-ration crates were either wood (43 lbs./20 kg each) or fiberboard (41 lbs./18.5 kg each) and had a volume of 1.4 cubic feet. Each crate contained 12 daily rations (each daily ration consisting of one Breakfast unit, one Dinner unit, and one Supper unit) for a total of 36 units per crate. They were packed one unit deep, three units wide (one of each unit), and twelve units long (all of the same unit type).

 

The U.S. Army M-1943 herringbone twill (HBT) fatigue uniform had simplified, but large, pockets that were designed to hold a K-ration box.