Our 4-Stage NASA-Based whole house water filtration system will filter over 2,400,000 gallons of water, removing 99.9999% of viruses, bacteria, protozoa, and cysts. It also removes fluoride, both types of lead and chemicals. It comes with 1- 20" sediment filter, 1 - 20" filter to remove chemicals, 1 - 20" double pleated, NASA-Based water filter, and 1 - 20" double-pleated NASA-Based water filter with carbon/ carbon block and nanosilver.