DESC: Patented, breakthrough technology provides air cleaning performance never before possible. It's 94% efficient at removing disease-causing bacteria as small as 0.35 micron. It even traps viruses with unsurpassed efficiency of 80%. No other whole-house air cleaner can reach more than 72%. Over 99% efficient on pollen and spores. Provides allergy relief. Ask your doctor. Air Cleaner media lasts one to two years. Protects heating and cooling equipment. No monthly cleaning of collector plates. The best choice for the healthiest indoor air.