Stage 1 - 5 micron sediment filter removes particulates Stage 2 - Carbon filter removes chlorine, chloramine, tastes, chemicals, and odors Stage 3 - 5 micron carbon block filter serves as a backup to the first carbon filter to protect membrane Stage 4 - 50 GPD TFC reverse osmosis membrane, purifies the water removing 95%-98% of contaminates Stage 5 - Inline Post filter - polishes water to ensure great, fresh tasting water Stage 6 Upgrade Kit - pH filter increases ph level to a neutral 7.0 and replenishes minerals in water, resulting in great tasting water. Includes clips, necessary fittings, and additional tubing to add filter to system. The FREE FLOWLOK Leak Protection system shuts off the water supply to the filtration system if water from a leak is detected. It requires no electricity and helps minimize issues associated with water damage. Includes all the parts you need to install the system in most applications, including 3/8" feed water connector & ball valve (fits most standard water lines), drain saddle valve, tank ball valve, filter housing wrench, color coded tubing, and a chrome quarter-turn deluxe faucet. Most water supplies contain a wide range of contaminates, but our RO systems solve this problem, giving you bottled quality water at your finger tips! Our high quality RO systems will ensure that your families drinking water is safe. Our systems are quality made in the using NSF certified components. Don't mistake our low prices for low quality, we back our systems with a 30 day satisfaction guarantee and a 1 year warranty! We also offer phone and email support to answer any questions you may have and are there for you if you need help. Instructional video available on our website for installation, filter changes, and installing filter upgrade kits