Advanced semiconductor sensor with fine sensitivity and quick response, simple and convenient to use. It displays the final test result in digital and visual mode, allowing anyone to check themselves using this tester. 5 result levels: very good, normal, not very good, bad, very bad. Digital LCD display with orange backlight, energy saving and environmentally friendly, soft colors that are easy on the eyes. Fast response with self-check function to indicate different conditions. Portable design, compact size, easy to carry in your pocket. Non-contact design, breathe 5-10mm away from the detector for better hygiene. Battery saving design with low battery indicator, powered by 2 AAA batteries for long service life (batteries not included). Usage: Open the battery compartment, insert 2 AAA batteries and close the compartment. Press the power button, the device will show a 9-second countdown. The screen will flash "C", at this moment, breathe evenly into the air inlet for 3 seconds. After a beep sound, the result will be displayed for 5 seconds and then the device will automatically turn off. To perform another test, press the power button again. Specifications: Sensor type: semiconductor sensor Warm-up time: 9s Blowing time: 5s Working environment: relative humidity ≤95% RH, no condensation Power: 2 AAA batteries (not included) Item size: 95 x 36 x 18mm / 3.74 x 1.42 x 0.71in Color: white Material: plastic Package Contents: 1 x bad breath tester (battery not included) 1 x English instruction Note: Light and different displays may cause slight color differences between the item in the picture and the actual product. Measurement allowed error is +/- 1-3cm.