The Sirchie NARK II Mayer's Reagent (Narcotic Alkaloids, 10 Tests) is used as a presumptive test for narcotic alkaloids. Each test is comprised of one or more chemical reagents. Packaged in disposable pouches, each individual reagent is sealed in a thin, glass ampoule ensuring freshness and eliminating cross contamination with other reagents. Reagent is designed to function as a transportable narcotics laboratory so it is available for use wherever the need for its capability might arise. The colors displayed on the front of the pouch is designed to match the family of colors only. Due to purity, quantity and agitation of the substance with the solvents and reagents, the colors may vary in intensity. Field tests are designed to confirm probable cause only-they do not test for purity.