5 Stages of pure water: 1.First stage: premium quality sediment filter removes dust, particles, and rust. Filter life: 6 months. 2. Second stage: premium quality carbon block gac removes chlorine, tastes, odors, and other chemicals. Filter life: 6 months. 3. Third stage: premium quality carbon block further removes residual chemicals, tastes, and odors filter life: 6 months. 4. Fourth stage: high rejection RO membrane removes 99% of contaminants including arsenic, copper, aluminum, lead, fluoride, heavy metals, and much more... Filter life: 2 years. 5. Fifth stage: refining coconut carbon filter removes any possible residual taste and impurity from the tank. Filter life: 1 year. High capacity reverse osmosis water filtration features a perfect flow of water for a home water filtration system delivering the purest refreshing glass of water. The RO water purifier produces pure water for all your drinking needs. This under sink mounted water filter and water softener is guaranteed to give you delicious drinking water in demand.