DESC: The True HEPA air purification system offers the ultimate in air purification technology. It removes up to 99.97% of particles from the air that passes through the filter. It's the same technology used in hospital operating rooms and other high-tech environments. It works by passing all air through a completely sealed True HEPA Filter for maximum air purity. There's no air bypass. It's designed for those desiring total air purity including infants, the elderly and people with respiratory ailments.