The HealthMate Plus filter is specifically designed for the Chemically Sensitive. Along with all of the protection of the Standard HealthMate filter, the carbon/zeolite in the HealthMate Plus filter has been specially treated with potassium iodide - a special compound that enhances the adsorption of thousands of odors and gases. Finally, 30 sq. ft. of true medical HEPA filter paper removes harmful airborne particles as small as 0.3 microns.