Inline check valve prevents water from flowing back through the water line. It is used on reverse osmosis systems to prevent backflow through the membrane. When the check valve malfunctions, it can allow the tank to empty back through the membrane and down the drain line. The 1/4-inch quick connect fitting allows the inline check valve to be replaced easier and more quickly then the threaded elbow check valve.Product FeaturesCheck ValveCheck valve prevents water from flowing back through the line. These are most commone on reverse osmosis systems and prevent water from flowing back through the membrane.1/4" Quick ConnectWith quick connect fittings, all you do is puch the tubing in and you're done. It's quick and simpleProduct DescriptionMore Info