Just insert the capacitive sensor into the soil, you can the real-time data of soil moisture, an external screen, a motherboard, you can talk to your plants See if your beloved plant is thirsty and needs a little Applications: garden plants; moisture detection; intelligent agriculture, note: the humidity is when the voltage is small, the humidity is small when the voltage is , go back to confirm with a multimeter measurement. Specification. Operating voltage:3.3 ~ 5.5 Output Voltage:0 ~ 3.0 Interface:PH2.54-3P Size: 98 x 23mm (LxW) : ABS colour: Black Package Contents: 1 set x Capacitive sensor(12PCS) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.