I got so much allergies from this year. And skin got sensitive. I am taking allergy meds everyday. But it doesn't help much. Soon after open window, my eye gets itchy, nose is running, sneezing and sometimes hard to breathe. But this air purifier work well for me!! No more allergic reaction. It's small size, but high quality! One reason why I gave 4 stars is ...I thought this is cordless. Because it's said "charging" Not charging power and carry everywhere cordless? But overall, I love it