This handy Alcohol Tester attaches to your keyring. Simply blow into it to test your blood alcohol level. Invaluable for the silly season!
Breathe into this keyring tester and brace yourself for the results: green light = under 0.02% BAC; yellow light = 0.02% - 0.05% BAC; yellow & red lights = over 0.05% BAC. Handily, the keychain also comes with an LED flashlight.