Water flow sensor is mainly consists of plastic valve body, rotor assembly and Hall Current Sensor.It is installed in the hot water inlet end for detecting water flow. When water through the flow rotor assembly, Magnetic rotor will rotate and Speed will change as the flow change. Hall Current sensor output corresponding Signal and feedback to controller, then the controller will control the flow. Can use for Water heaters, credit card machines, water vending machine, flow measurement device. Features: weight, small size, easy to install. Inlaid with stainless steel impeller shaft, durable wearable. Seal Ring 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 (DC 5V). Working voltage range: DC 5~18 v. Load capacity: ≤ 10 mA (DC 5V). Work temperature: ≤ 80 ℃ Work humidity range: 35%~90%RH (no frost) Allowing pressure: pressure 1.75Mpa Storage temperature: -25~+80 ° c Save humidity: 25%～95%RH Flow Range :1-30L / min External threads: 1/2" Package Includes: 1 x Water flow sensor