How to Use: 1. Press the button for 1 second to turn on, the backlight and the display will light up at the same time, display all the content and a "beep" prompt to turn on. 2. The display shows "Warm up" and a 10 second countdown. After the countdown is over, a "beep" will sound, indicating that will enter the next stage at the same time. 3. The display shows "Blow" and a 10 second countdown. Blow to the blowing place for 3‑5 seconds. After the countdown is over, a "beep" sound will prompt you to enter the result display. The test result is displayed in two units of %BAC and g/l. 4. When the test result is less than 0.02% BAC, the green indicator light is always on. 5. When the test result is greater than or equal to 0.02%ABC and less than 0.05%BAC, the yellow indicator light is always on, the "Caution" icon on the display screen is flashing, and there is a slow beep sound. 6. When the test result is greater than or equal to 0.05% BAC, the red indicator light is always on, the "Danger" icon is flashing, and there is a rapid beep sound. The test results show a time of 10 seconds. Specification: Item Type: Breathalyzer Material: ABS Battery: Lithium battery 3.7V 200mAh Application: Detection Detection Range: 0.000~0.19%BAC; 0~1.9g/L Package List: 1 x Instrument 1 x USB Cable 1 x User Manual