digital alcohol tester, breath alcohol tester, keychain alcohol tester 1. Warm-up time: Within 10 seconds digital alcohol tester1. Sensor: Semiconductor alcohol sensor2. Warm-up time: Within 10 seconds3. ... resume8. Red-colored backlight (can be choose with or without)9. Power input: Use 2xAAA alkaline batteries (not included) digital alcohol tester, breath alcohol tester, keychain alcohol tester