Advanced semiconductor sensor, with fine sensitivity and quick accountability, simple and convenient to use. It will show the final test in digital and cartoon mode, anyone can check themselves by this tester. 5 levels: very good, normal, not very good, , very . Digital LCD display and cartoon with orange backlight, save energy and environmental protection, with calming colors and will not hurt your eyes. Quick response and cv, with self-check to show different conditions. Portable design, small size with structure, easy to put in your pocket and carry with you. Non-contact design, 5-10mm from the detector, more . Battery saving design, low battery indication, 2 x AAA batteries long service life (battery is not included). Use: Open the battery case, put into 2 * AA battery and the case. Press the power button, it will display 9 seconds countdown. Then the screen flashes "C", and at this moment you can 3 seconds evenly at the air inlet. After a beep sound, it will display the , the will display 5 seconds and automatically shut off. If you to test time, press the power button again. Specifications: Sensor type: semiconductor sensor Warm-up time: 9s Blowing time: 5s Working environment: relative humidity: less than or to 95% no dews Power: 2 AAA batteries (not included) Item size: 95 x 36 x 18mm / 3.74 x 1.42 x 0.71in Colour: white Material: plastic Package Contents: 1 x breath detector (without battery) 1 x English instruction Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.