Austin Air FR400B Healthmate Standard Replacement Filter, WhiteA replacement filter for HealthMate (HM400) Prefilter included for the outside of the main filter 60 square feet of true medical HEPA (High Efficiency Particulate Arresting) filter for removing airborne particulates 12 pounds of Carbon Zeolite for adsorption of odors, gasses & chemicals This replacement filter is for the HealthMate (HM400). The Austin Air HealthMate filter is constructed using a true medical High Efficiency Particulate Arresting