G3/4 Inch Liquid Water Flow Sensor Switch Copper Hall Effect Flow Meter Meter.    Features:  - Made of high-quality copper material, environmental-friendly, really sturdy, and durable to use.  - its maximum water pressure is 1.75MPa, the range of flow is from 2L/min to 45L/min.  - Three-wire connection: Red for positive pole, black for negative pole, yellow for pulse signal.  - There is an integrated hall effect sensor that outputs an electrical pulse with every revolution. The hall effect sensor is sealed from the water pipe and allows the sensor to stay safe and dry.  - Lightweight, reasonable size, stable performance, low water pressure start, easy to install, safe to use.  - Can be perfectly used for water heaters, water dispenser, water purifier, water vending machine, coffee maker, flow measurement device, water control machine and so on.   Specifications:  Material Copper;  Color Gold;  Type G3/4"(External Thread Diameter);  Water Quality Requirement ≤60℃;  Start Flow Range 1.5L/min;  Flow Range 2-45L/min;  Maximum Water Pressure 1.75MPa;  Working Voltage Range DC4.5-18V;  Max Current 10mA;  Insulation resistance >100MΩ;  Electrical Strength AC500V, 50Hz;  Wire Length Approx. 35cm / 13.8inch;  Weight Approx. 110g.    Package included:   1 x Water Flow Switch.