The Moisture Sensor with Sensor Modules ROHS manufactured by Waveshare is a humidity-sensitive component that detects ambient moisture in the air. This moisture detection module has high accuracy and is RoHS compliant. The moisture detection range is from 0-100%, with an operating voltage range of 3V-5V. It is designed to handle 0-100% relative humidity sensing for applications such as soil quality, water seepage, water content in food products, soil moisture and relative humidity in warehouse storage facilities. This sensor also has a fourth pin on the module that can be used to set a threshold for automatic triggering. With its easy-to-install and easy-to-use design, it is suitable for a variety of applications.