Feature:1. Noncontact Design: Noncontact blowing detection is safe and hygienic, can be used by more than one person without extra mouthpiece replaced.2. High Accuracy: Alcohol tester has high sensitivity sensor ensure accurate detection in a short time, prevent strong interference.3. LCD Digital Display: Measurement results are clearly visible, easy to see even in dark places, clear contrast, high visibility and easy to understand.4. Rechargeable: Built in 150 mah lithium battery, the portable alcohol tester is designed to be charged from type C port.5. Portable: Breathalyzer is very small and portable, can be easily carried in your pocket, convenient and practical, can use anywhere and anytime.How to Use:1. Preheat modePress the button for one second to start up, the backlight and the display screen light up at the same time, display all contents and hear a "click" prompt to start up, immediately enter the waiting mode and start the 10 second countdown from 10 to 00.2. Blow modeAfter the 10 second countdown in the warm up mode, you will immediately go into the 10 second blow mode and exhale evenly with moderate force for 35 seconds at a distance of 2‑3 cm from the blow port.3. Results displayRead test results