I purchased with great air purifier when I took my cat to the Veterinarian for her yearly appointment. The Vet asked me if someone smoked in the house and I said yes but they only smoke in the bathroom. She mentioned how the smoke can travel through the vents in the house and recommended an air purifier which would extend my cat's life. I went right away and researched and happily purchased the Pure Enrichment Air Purifier which has the HEPA filter and is so very quiet. Right away I noticed the house is filled with cleaner air and my cat is very content!!