The ZeroWater ZJ-003 Water Cooler Filter System uses a patented five stage dual ion exchange filter system. This water filter has the advantage of purifying water right in the container. No need of installing big water filter systems that occupy space. This water cooler-filter system is the easiest way to purify water, pour the water in it, then uses the patented five stage system to purify it. Pour out the water and drink it right then. It has a capacity of 5 gallons. It comes along with a built-in TDS meter that constantly tests for the purity of water. It removes chlorine, dust, iron, sediments, silt, rust, sand, lead, and all the dissolved salts. The ZeroWater ZJ-003 Water Cooler Filter System is the only filter that meets the FDA required TDS levels of purified water, 000-010ppm. It has a unique two-chamber bottle with lid that will fit any standard water cooler.