Description: Non-Contact: You use this personal breathalyzer without extra mouthpiece, direct blow to the inhaler, you can get the precise blood alcohol concentration with the improved high sensitivity semiconductor sensor in seconds. LED Display & Sound Effect: The test value is directly displayed on the LED, the reading is convenient, simple, intuitive. There are 2 units of measure to choose from,% BAC, g/l. The results can be distinguished by sound and color Just press the power button for 2 seconds to start the professional breathalyzer, wait for 10 seconds for warming-up, then blow with the tester for 5 seconds, the result will be ready after 3 seconds, and it will be displayed on the LCD screen USB Rechargeable and Long Lasting: Breathalyzer has built-in lithium battery, come with USB data cable, the breathalyzer is rechargeable. Blood alcohol test can last from 300 times after full charge Portable: This professional alcohol tester is very small and portable(only 10cm/3.9in), can be easily carried in your wallet or pocket. Specification: Range: 0 ~ 0.19% BAC (0 ~ 1.9g / l) Automatic shutdown: 10s Breath sampling: ≥5 s blowing c ontinus Size: 10x2.7x1.4cm/3.9x1x0.5in Package Includes: 1x Instruction 1x USB data cable 1x Alcohol Tester Note: 1.Press the power switch for 2 seconds to turn on the machine 2.Machine self-checks and "warm up" for 10 seconds 3.Take a deep breath and blow at the breath for 10 seconds 4.Get accurate results, there will be different colors of lights and prompt sounds, the machine will automatically power offafter use In order to make the test results accurately, please test with the alcohol breathalyzer 25 minutes later after drinking; please wait for another 10 minutes before starting the next test to get the precise testing result