Feature: COMPACT AND PORTABLE: The Portable Breathalyzer is easy to carry and saves space for you, you can keep it in your pocket or bag Accurate readings: Alcohol Tester uses advanced high technology sensors that will give you the most accurate values in no time LED display: Digital Breath Alcohol Tester adopts high-definition LED display, intuitive display, easy to observe at night How to Use: 1. Power on: Press and hold the power on button for 1 second, after a beep, the tester's LED screen will start. 2. Preheat: The "Preheat" character appears on the display and the number in the upper left corner starts counting down from 10 to 00. 3. Blow test: After the "warm up" is completed, the tester enters the "blow" state and the blow character appears on the display, with the numbers counting down from 10 to 00. Blowing within this countdown time, the machine senses the gas, the buzzer "beep" prompted to stop blowing. 4. Display of results: The test results are read on the display. Press and hold the power button for 1s to switch the unit, i.e. the unit flashes after the value, press and hold again for 1s to exit. 5. 10s after the test result is displayed the unit automatically switches off. Switch on again for the next test. Specification: Item Type: Alcohol Tester Material: ABS Weight: Approx. 47g/1.7oz Voltage: 5V Current: 1A Battery: Li polymer 150mAh (Included) Measuring Range: 0-0.95mg/L Preheat Time: 10 Seconds Blow Up Time: 10 Seconds Package List: 1 x Alcohol Tester (Battery Included) 1 x Manual 1 x USB Power Cord