Independent sources of heat 'AIST 6E3 '- individual disposable warmers. The set includes 4 pieces of 5cm x 9cm and 2 pieces 10 cm x 11 cm. Those are hermetically packaged bag of soft material, inside which is an exothermic mixture of iron powder, salt and water retention substance. When removing from a sealed package for 3-10 minutes, heated to 45-55° C. Heat release is due to the oxidation of iron powder with oxygen in the air. They are used for warming the soldiers when cold. They can be placed in the inner pockets of clothing, or in mittens.