I am a lover and fan of all Shark's product, they have never ever failed me. This Air Purifier Max does exactly what it's name said.  It purifies and clean the air up to 1200 square foot, it's very quiet, can't hear when its on.  It  displays the level of  quality air  that is in the house. I have noticed that when I'm cooking it goes from 100% good quality air and drops down to 40%,  then it turns red to indicate the level of Clean Air is down. This usually happens when I'm cooking mainly from the smoke in the kitchen.   I love how it helps clean the air from pets, smoke, bacteria and also helps combat dust. My breathing quality of air in my home is definitely so much better at a 100%. I can breathe  fresh cleaner  air and feel so much better.  This Air Purifier is a must have  and a keeper for me and my family.