The 81 mm Mortar Infrared Smoke (IR-SMK) round provides visual and infrared screening for several minutes over a wide area. The round functions by way of a time fuze, at a height of 400 m wherein the front and rear body are split, ejecting burning smoke pots containing red phosphorus. The round is delivered as a ready-to-fire in 2-round containers, equipped with a fuze and charge system.