This is the soil moisture hygrometer sensor this module has two devices the primary device is the two pin prove and the other one is the sensor integrated circuit and it has adjustable potentiometer to detect the moisture of soil. This module can be used as a soil moisture. Specification: Digital output, easy to adjust. Nickel plating to avoid corrosion, Working voltage: 3.3V-5V. On-board LM393 chip. Dimension of the board: 3.2cm * 1.4cm. Package Content: 1x Prove Pin. 1x Sensor Module, 4x DuPont Wire.