I have several of these Ionic Pros throughout my house because I'm a smoker. I wasn't really sure how much good they did until my dog chewed the cord off the one in my living room. After one week without one in my house, I was overnight shipping one. I was truly unaware of how much gunk they take out of the air until it was left to float around! Even cleaning the easy-to-clean bars hadn't really convinced me. These things work.