Specification Brand : NUOYAQI BulletPoint1 : Make of brass, , anti corrosion, high temperature resistant. BulletPoint2 : Mainly used for water flow switchs control of electric appliances such as water heaters, humidifiers, drinking fountains. BulletPoint3 : When this product connect to a load 50W, intermediate must be added, otherwise it cannot be used. BulletPoint4 : Inner Diameter: 18mm, Outer Diameter: 26mm BulletPoint5 : 1x Fluidmeter Counter Color : As the Picture Shows ExternallyAssignedProductIdentifier : 7593720301647 ItemName : NUOYAQI Professional Water Flow Switchs DN20 External Threaded Brass Flow Fitting Fluidmeter Counter ItemTypeKeyword : electronic-component-flow-sensors Manufacturer : NUOYAQI Material : Brass ProductDescription : Features: Good sealing effect, easy to install. Make of brass, , anti corrosion, high temperature resistant. Mainly used for water flow switchs control of electric appliances such as water heaters, humidifiers, drinking fountains. When this product connect to a load 50W, intermediate must be added, otherwise it cannot be used. Working method: When there water flow in the water flow switchs and the water flow rate ≥1.5L/min, the magnetic in the water flow switchs will receive water. The flow pushes the displacement, and the magnetic displacement drive the magnetic source to produces the magnetic control effect, so that the water flow switchs output "on" Signal. The signal input to the equipment control system, and the control system realizes the control function. When the water flow less than the starting flow, the water flow switchs outputs a "off" signal. The control system produces the samereverse control.