Review on Next-Level Air Purification: Germ Guardian WiFi Bluetooth Smart Voice Control Air Purifier with UV Light Sanitizer and True HEPA Filters for Allergies, Mold, Odors, Smoke, Pet Dander - 22inch 5-in-1 CDAP4500BCA by Micael Casillas

(HEPA filter has been supplied with unit for the last 4 months or so, a replacement can cost over $22, really expensive) This is more about Wi-Fi and its app On the iPhone, air filtration is difficult to measure scientifically due to the lack of equipment, but they reduce the pollen allergy I've experienced.1. WIFI on a device not working for 1 day, replacement requested and delivered.2. Tested the second, the wifi setting and connection works fine, after turning it on it always started at 150, then quickly reduced to 3 (in my case you can get another number), that means the air in my room is just very clean. (If you smoke cigars, try smoking one over the device, you can see a rapid rise of PM, 200, 300, 400, etc. See photo; it falls off quickly when you stop, meaning it's working ) 3rd After test in 2nd ordered 3rd for son's room works well. same as the 2. The iPhone app (app name: Guardian Technologies*) is not a strong tool, sometimes it takes forever to literally open the app, or the app just won't wake up to work properly, doesn't matter it is on or not. Once the machine is plugged in and powered on, I have to go back to using the buttons on the machine. The Bluetooth/WIFI setup app is probably the worst I've seen in my 15 years of use. Also, the app's PM readings are not updated in real-time, you need to restart the app to get the latest readings. So you can save some money by buying models without WiFi or by waiting for a newer version. or updated products if there is no urgency.