The HEPASilent™ filtration system is designed to capture 99.97% of the smallest particles at 0.1 microns. One key feature is the filter media, made of hydrophobic polypropylene and is 100% free of trilosan, glass and paper fibers, and other chemical additives. Available models include the 620-sq-ft-capacity Model 501, the 365-sq-ft-capacity Model 402, and the 680-sq-ft-capacity Model 601.