Feature:1. LED HD Screen: LED high definition screen display, intuitive display, more convenient night observation.2. Three Color Indicator Light: Quick detection, refuse to wait. Suitable for company, friends, family gatherings and other occasion.3. Portable: Small and portable breathalyzer that fits easily in your pocket or purse.4. Easy to Use: No contact with mouthpiece, safer and more hygienic, avoid the growth of in the blowpipe, no contact in the blower, and healthier measurement.5. Smart Chip: High sensitivity and high accuracy sensor, scientific filtration, purification of impurities, retention of alcohol, and more accurate measurement.How to Use:1. Power on: Press and hold the power button for 1 second, after a beep sound, the LCD screen of the tester starts.2. Preheating: The characters "preheating" appear on the display, and the numbers in the upper left corner start to count down from 10 to 00.3. Air blowing detection: After the "preheating" is completed, it enters the "air blowing" state, the display shows blowing characters, and the numbers start to count down from 10 to 00. Blow at any time during the countdown, after the machine senses the gas, the buzzer will make a beep to stop blowing.4. Display results: The test results are read on the display.