Contains one IQAir Cleanroom grade HEPA filter element. Made of 99.97% DOP (0.3 microns) media, mini-pleat with solvent-free separators, 40 square feet area, patented expanded polystyrene (EPS), CFC-free construction. The IQAir HEPA filters are for use with the IQAir HealthPro and HealthPro Plus units. These cartridges carry a life of up to 1-2 years