1. This breathalyzer uses a highly sensitive semiconductor alcohol sensor. 5 seconds after you blow, you can get a test result to determine if you can drive or not. 2. The portable breathalyzer comes with a USB cable. You can charge it by connecting the cable to your car charger or phone charger. 3. Contactless design: You use this breathalyzer without an extra mouthpiece, and your mouth doesn't need to come into contact with the tester to get a result. 4. The wide-opening breathalyzer can collect more exhaled air for increased accuracy. Use it 25 minutes after drinking. 5. Easy to use: Press the power button for 2 seconds to start the professional breathalyzer, wait for 10 seconds for warm-up, then blow into the tester's mouthpiece for 3-5 seconds. The result will be displayed within 5 seconds and then shown on the LCD screen for 10 seconds. 6. Compact size, takes up little space, can be easily placed in your wallet or pocket. Perfect for weddings, parties, celebrations, or other social activities to ensure your safe driving after drinking. 7. This newly upgraded portable breathalyzer uses a new programming calculation method to make test results more accurate. The test result is displayed in 2 ways (%BAC and g/l) for easier understanding. Item Type: Breathalyzer Material: ABS Color: Black Size: Approx. 8.5x2cm / 3.3x0.8in Weight: Approx. 122g/4.3oz Built-in battery: 300mah polymer lithium battery Beep and Light Warning: Below Warning Value (<0.01%BAC): Green indicator lights up Between Warning Value and Dangerous Value (0.01%BAC - 0.08%BAC): Yellow indicator lights up and beeps Higher than Dangerous Value (>0.08%BAC): Red indicator lights up and beeps rapidly