I purchased this 7 month ago, I think it was the biggest mistake, it is just a showpiece. It is only for a closed ac room. It doesn’t work when windows ar doors are open. And it is definitely not for the air polluted city like Delhi. And its air quality indicator allways shows red. I would suggest please don’t purchase this product. It is money wasting. And the most important thing is that it is a Chinese product. It manufactured in China and we all aware about the quality of chinese product.