4 Pack Vacuum Cleaner HEPA Filters for Cyclonic Series RO3753EA RO3731EA RO3786EA Advanced semiconductor sensor, with fine sensitivity and quick accountability, simple and convenient to use.<br> It will show the final test result in digital and cartoon mode, anyone can check themselves by this tester.<br> 5 result levels: very good, normal, not very good, bad, very bad.<br> Digital LCD display and cartoon with orange backlight, save energy and environmental protection, with calming colors and will not hurt your eyes.<br> Quick response and cv, with self-check to show different conditions.<br> Portable design, small size with compact structure, easy to put in your pocket and carry with you.<br> Non-contact design, breathe 5-10mm from the detector, more hygiene.<br> Battery saving design, low battery indication, 2 x AAA batteries provide long service life (battery is not included).<br> Use:<br> Open the battery case, put into 2 * AA battery and close the case.<br> Press the power button, it will display 9 seconds countdown.<br> Then the screen flashes "C", and at this moment you can breathe 3 seconds evenly at the air inlet.<br> After a beep sound, it will display the result, the result will display 5 seconds and automatically shut off.<br> If you want to test one more time, press the power button again.<br> Specifications:<br> Sensor type: semiconductor sensor<br> Warm-up time: 9s<br> Blowing time: 5s<br> Working environment: relative humidity: less than or equal to 95% no dews<br> Power: 2 AAA batteries (not included)<br> Item size: 95 x 36 x 18mm / 3.74 x 1.42 x 0.71in<br> Colour: white<br> Material: plastic<br> Package Contents:<br> 1 x bad breath detector (without battery)<br> 1 x English instruction<br> Only the above package content, other products are not included.<br> Note: Light shooting 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.