Portable to carry it with you, testing your BAC at any time and anywhere. Quickly estimate your blood alcohol concentration with this small and contactless alcohol breathalyzer. No need to worry about forget to install a mouthpiece or issue, you can directly blow to the tester inhaler without a mouthpiece, more convenient and safe. Easy to use, light in weight, Low power consumption, automatic shutdown, Backlit LCD display, 3-color indicator light test results are clear at a glance. Dust-proof design, sliding up to close the air inlet, long-term use. 1. Press and hold the power button for 1 second, the alcohol tester LCD with turn on with one beep sound. 2. Warm-up mode countdown for 10 seconds. 3. Testing mode countdown from 10 to 00 after warm-up mode, blow at this period. 4. Blow into the breath inhaler for 3-5 seconds with normal power after a deep inhalation. 5. Read the test result from the alcohol tester LCD. 6. Test range: 0.00%-0.19% BAC 0.0-1.9 g/L Warm-up time: within 10 seconds Power supply: 200mA lithium battery Unit: G/L, %BAC Indicator light: green, orange, red Material: ABS colour: Black Package Contents: 1 x Alcohol Tester 1 x USB data cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.