Portable Non-Contact Air Blow Alcohol Tester Digital Display Screen USB Rechargeable BAC Tester Grade High Precision describe: Get a quick estimate of your blood alcohol level with this small, non-contact breathalyzer. Don't worry about forgetting to install the nozzle or iues, you can blow directly into the tester inhaler without the nozzle, which is more convenient and safer. Take it with you and test your BAC anytime, anywhere. how to use: 1. Pre and hold the power button for 1 second, the LCD screen of the alcohol tester will turn on, and a beep will sound. 2. The preheat mode counts down for 10 seconds. 3. After the warm-up mode, the test mode counts down from 10 to 00, and blows at this time. 4. Blow into the with normal power for 3-5 seconds after inhaling deeply. 5. Read the test results from the alcohol tester LCD. 6. Test range: 0.00%-0.19% BAC & 0.0-1.9 g/L notes: 1. When using the tester for the first time or after not using it for a long time, please pre the power button and try again if poible. 2. Repeat 2 or 3 times for more accurate results. 3. Do not smoke or eat 20 minutes before the test. 4. The test results are for reference only. 5. Can be charged via USB cable The package includes: 1*box 1*Description 1*USB cable 1*Alcohol Tester