Purchased this item back in November of 2020. My wife has chronic allergies and this purifier was our last hope and wow it does wonders. Not only does it remove odor, but also pulls in our dog's loose dead hair instantly. You are supposed to check monthly to clean the outer filter, but I check weekly just to see how much it has already picked up and it sucks in a lot more than you can imagine within a week. We plan to purchase two more once we move into a bigger place.