Welcome to the store! Advanced semiconductor sensor for fine sensitivity and quick results, easy and convenient to use. Displays the final test result in digital and cartoon modes, making it easy for anyone to check their breath. Features 5 result levels: very good, normal, not very good, bad, very bad. Digital LCD screen with cartoon display and orange backlight saves energy and protects your eyes with soothing colors. Quick response and recovery with self-checking to indicate different conditions. Portability design, small size with compact structure, easy to put in your pocket and carry around. Non-contact design, breathe 5-10mm from the detector for more hygienic use. Battery-saving design with low battery indication; 2 x AAA batteries provide long service life (battery not included). Easy to Use: Open the battery compartment, insert 2 * AA batteries, and close the cover. Press the power switch; it will show a 9-second countdown. The screen will then flash \"C,\" at which point you can breathe evenly into the air inlet for 3 seconds. After a beep, the result will be displayed for 5 seconds and then automatically shut off. To test again, press the power switch again.