The key component of a commercial Reverse Osmosis (RO) water purification system, usually used in the 4th stage. This RO membranes have very tiny holes, which allow only water and a few gases to pass through under certain pressure thus produce virtually pure water. The technology has been used in spaceships to recycle water for astronauts. It is highly effective in reducing hardness, heavy metals, toxins, free chlorine, bad taste, odor THM, Organics, hazardous chemicals, pesticides and more. Depending on inlet water quality or flow rate, this RO membrane MC7 needs to be replaced every 24 months or 48,000 Gal. of water.