Walmeck Dust Particle Counter 6-Channel 0.3um/ 0.5μm/ 1.0μm/ 2.5μm/ 5.0μm/ 10um .5 Detector with 3.2-inch Backlight Color Screen Air Quality Tester Temperature Humidity Home Offi

Air Quality Monitor: There are 2 models for option. -8100 features 3 channels to detect the number of 0.3um, 2.5um particle size dust, the concentration of .5 and , Grade, and humidity. -8200 features 6 channels to detect the number of 0.3um, 0.5um, 1.0um, 2.5um, 5.0um, 10um particle size dust, the concentration of .5 and , and it can detect the class of Class 100 room and below room, , humidity and Grade. 3.2" Color Screen & Comfortable Buttons: La