Water flow mainly consists of plastic valve body, rotor assembly and Hall Current installed in the hot water inlet end for detecting water flow. When water through the flow rotor assembly, rotor will rotate and Speed will change as the flow change. Hall Current sensor output corresponding Signal and controller, then the controller will control the flow. Can use for Water heaters, machines, water vending machine, flow measurement Features: weight, small size, easy to install. Inlaid with stainless steel impeller shaft, durable wearable. Seal with the upper and lower force structure never leaks. Precautions: Non-violent shock, and chemical erosion. Non-throwing or hitting. Mounted vertically, should not exceed 5 degrees inclination. Temperature of Medium should not exceed 120 ℃ Cord Connection: Red: Positive(+) Yellow: Signal output. Black: Negative(-) Specification: The lowest rated working voltage: DC4.5 5V-24V. Maximum operating current: 15 mA (V). Working voltage range: ~18 v. Load capacity: ≤ 10 mA (V). Work temperature: ≤ 80 ℃ Work humidity range: 35%~90%RH () Allowing pressure: pressure 1.75Mpa Storage temperature: -25~+80 ° c Save humidity: 25%～95%RH Flow Range :1-30L / min External threads: Approx. 1/2" Color: Transparent Package Includes: 1 x Water flow sensor