The Defend NV 400 is 99.9 percent effective at inactivating airborne pathogens while purifing the air of particulate matter, volatile organic compounds, gases and odors. The product bursts airborne pathogen cells, inactivating them to ensure they are no longer a threat to infection.The four-stage pathogen inactivation and filtration process utilizes medical-grade filters in order to capture bacterial debris, fine and large particles, VOCs, gases, odors and impurities.