This is YF-S201 Water Flow Measurement Sensor with 1-30Liter/min Flow Rate white sensor. This sensor sits in line with your water line and contains a pinwheel sensor to measure how much liquid has moved through it. There’s 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.

Features :

1. 1/2″ nominal pipe connections, 0.78″ outer diameter, 1/2″ of thread.
2. The simple and compact module.
3. Easy to Install.
4. High Sealing Performance.
5. High-Quality Hall Effect Sensor.