Due to a breathing problem, I have been using air cleaners for a long time and quite frankly never thought that I would spend the amount that I did on the Alen FIT50 but I did with no regrets. From the packaging right to the unit itself, impressive. The first air purifier that I have had with such a large filter that I feel with do the job and the controls, I feel are so well designed and user friendly. When I first started the unit in auto mode, it started out in blue and within a very short period of time switched over to orange which means to it needed additional purification and I had been running another air cleaner 24 hrs a day, within a few hours it went back to blue.