Fast GC (gas chromatography) - IMS (ion mobility spectrometry) as a core technology is sufficiently flexible with respect to a broad range of chemical detection capabilities. The application of this dual technology can provide unique solutions in many operational environments. GC-IMS is the next evolutionary step in the advancement of IMS technology. Using the advantages of IMS (i.e., small, high sensitivity, rugged, operates at atmospheric pressure, etc.) And the chemical selection capability of GC, this detector configuration can be customized to detect and identify explosives, ICAO markers, and narcotics. This paper will present a technical discussion on GC-IMS and describe several commercial off the shelf (COTS) systems with potential application in many operating environments. Instruments include the Orion for explosives detection, Ariel for narcotics detection, Sirius for both explosives and narcotics detection, and NorthStar for handheld narcotics detection.