To help security guards uncover a range of threats hidden under a persons clothing, a non-intrusive screening system was recently unveiled by American Science and Engineering, Inc., located in Billerica, MA. Called SmartCheck, the system detects metallic and non-metallic objects hidden on a person, including metal and plastic weapons (such as handguns and knives), as well as explosives, narcotics, and other contraband. By viewing the systems display screen, an operator can pinpoint the shape, size, and location of the concealed threat. Although SmartCheck displays an outline of the scanned individual and hidden item, built-in privacy software ensures that no revealing images of the individuals body are shown. Ideal for airports, military bases, correctional, and other high-threat sites, the system works through Back-scatter X-Ray technology, which recognizes the low or high atomic numbers of materials found in weapons or other contraband. Radiation levels emitted dur-ing a single scan of the machine are extremely safeequivalent to about two minutes of airplane flight at altitude.