The HealthPro Plus comes with the V-5 Cell Gas & Odor Filter included and pre-installed, for removal of airborne chemicals, gases, and odors from the air. This is especially important for those individuals with chemical sensitivities or for use in areas with smoke, odors, or brand new furniture or carpeting. IQAir's patented V5-Cell™ filtration provides the best solution for gas and odor elimination by combining two types of media: one that adsorbs odors and gases, and another that changes the pollutant to an oxidized form.
The HealthPro is identical in every other way to the HealthPro Plus, but does not come with the V-5 Cell Gas & Odor Filter included. You can always upgrade a HealthPro to a HealthPro Plus at any time by simply adding the V-5 Cell Filter, but you will save $50 by buying the HealthPro Plus to begin with, so the HealthPro Plus is certainly a better value than the HealthPro.