Hand-held Sniffex detects presence of dynamite, TNT, gun powder, and other compounds containing nitro oxide ions. Uncovers explosives located from 10 to 300 ft. away, even when explosive is hidden in buildings or vehicles. Contains built-in antenna that rotates in the direction of the explosive to pinpoint target location. Penetrates concrete or brick walls, metal structures, containers, or luggage. In less than 1 min., detector reveals if ammunition or explosives are located inside a small building or house. Also ideal for screening parking lots, airplanes, or crowds.