25Pcs Soil Humidity Sensor Hygrometer Measure ModuleFeature: This is a simple moisture sensor for measuring moisture of the soil, when the soil water, the analog sensor output value will decrease, and vice versa will increase. Using this sensor make an automatic watering system, when you are not at home or over a long period of time watering, it can sense whether your plant has been thirsty. Prevent plant wilts know that this is caused by lack of water. With controller to make your plants more