Operational Ration Pack. Military Style 24 Hour Ration packs produced by the suppliers to the British Armed Forces. The 24 Hour Ration Pack 4000 Kcal is a complete 39one stop 39 ration to fully sustain 1 active person for 24 hours while on operations. It contains high energy snacks electrolyte drinks and 3 main meals. All meals are fully cooked and ready to eat hot or cold.