I just got my Shark US - Shark NeverChange™ Air Purifier MAX.  It is awesome  filter lasts years.  It has scents you can use to mask some odors and give a pleasant smell as well, yiu do not need to use it.  It tells you how good your air is.  It is easy to use and high quality.  I am super happy with it.  It is a must first healthy living especially  if you have allergies, I highly recommend  it.