Smiths Detection has good sens-ors. Smiths designs sensors to identify biological and chemical agents, narcotics, weapons, and other illegal contraband, for use in banks, prisons, and industrial facilities, as well as in military, first response, transportation, and homeland security applications. Some of its detection and screening technologies utilize spectroscopy (gamma ray, ion mobility, Raman, and infra-red). The company makes X-ray inspection units to scan mail, luggage, and freight, as well as to detect explosives. The company manufactures metal detectors and makes systems for scanning trucks and freight containers. It is one of five subsidiaries of its parent company Smiths Group Plc.