Float Valve for Reverse Osmosis Systems designed to shut off the flow of water when the float is elevated. Ideal for containers like small pails, sumps, and large storage containers, it is made of NSF approved PVC with hardware made of 18-8 stainless steel. Suitable for saltwater and freshwater aquariums with an installation requiring a 1/2" mounting hole and a maximum container wall thickness of 1/4".