Police Level AccuracyPolice Level Breathalyzer with advanced semiconductor sensor, test your blood alcohol concentration more accurately and faster, it would give you a reliable result 2 measurement units canbe converted (% BAC, g/l) USB Rechargeable and DurableThe alcohol tester can be recharged with a USB data cable. It is very convenient for you to charge it via USB on your car, computer, wall outlet or power bank. Healthy DesignPress the switch with anti-dust design, blow directly into the tester without your lips touching the breathalyzer. You don't need to use the blowtorch (the blowtorch can cause bacteria).This makes the test more hygienic. Warm Tip for Alcohol Tester After drinking, it is recommended to wait 20 minutes before the test, because alcohol takes about 20 minutes from the digestive organs into the blood, and the residual alcohol in the mouth takes time to waste. For amore accurate result, please wait three minutes between each test. LCD Screen WarningWith LCD screen to see the result clearly and with 3 colors to remind you whether the alcohol test result is safe or not. They are separately green, yellow and red, green means safe, yellow is warningand red is danger. If the readings are equal to or higher than the alarm concentration, the breathalyzer beeps at the same time.