I was first sold on Alen air while living in Malaysia for 4 years. The constant haze and pollution was starting to take a toll on me and my family's health. Soon after purchasing our Alen Air breathe smart units, I could tell a HUGE difference in the air quality and we all slept great and had no more coughs or infections. We just received our 3 breathsmart 45i units now that we are back in the US and they have been great. Fresh clean air really makes a difference in how I feel. I'm SO thankful to have found Alen Air. I'm a customer for life!