Quick and easy 1/4" connection. Uses the back pressure created by the storage pressure tank (or float valve were used) to shut off the water supply to the reverse osmosis membrane. Automatically shut off the water supply when the tank pressure reaches approximately 65% of the supply water pressure. Suitable for most reverse osmosis water systems. Package: 4-way shut-off valve x 2 Features: Suitable for most reverse osmosis water systems. 4-way 1/4" quick connect for easy connection. Automatically shut off the water supply when the tank pressure reaches a certain degree. Mainly used for reverse osmosis water purifier, water filter, direct drink machine, pipeline machines. Four-side valve settings Connection pipe: 1/4" PE water pipe (6-6, 3 mm Blocking ratio: 1:2 Operating pressure: 1-4.5 KG/CM2 Contents: 2 stop valves 4-way.