The Water Flow Sensor is light, nimble outline, small size and easy to install. The bearings used in the rotating part. There is an integrated magnetic 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. Water Pressure: ≤1.75 MPa; Alarm Value: 30 L/h Output Waveform: Square Wave,output pulse signal. Waterproof, heat resistance, pressure resistance, cold resistance.