This Date Rape Drug Tests Coaster is one of the most advanced ways to test for a date rape drug. The two most commonly used illicit drugs (Ketamine and Gamma-hydroxybutyric acid) are tested by using a Drink Safe Coaster. The two-test device is a 4 x 4 coaster that uses five-color graphics to detect the illicit drugs. At each bottom corner of the coaster are two test areas. In the center of the coaster is a drink safe message. On the back of the coaster are instructions on how to perform a drug test. Two tests can be performed on one coaster.