I received a Shark Air Purifier Max from Tryit Sampling in exchange for a honest review.I have never had an air purifier before but with 2 cats and a grandson living with me I was very excited to try one.This product did not disappoint.It is very easy to use.The machine goes on when the air quality goes below 100 percent .I never realized that cooking decreases the air quality so much.Also this time of the year when allergies are so bad, you can leave your windows open and the air purifier does its’ job. It runs very quiet so you hardly know it’s there.Highly recommend.