Material: metal Net Weight: 28g Model: FC-28 Main Color: blue Operating voltage: 3.3V~5V Dual output mode,analog output more accurate A fixed bolt hole for easy installation With power indicator (red) and digital switching output indicator (green) Having LM393 comparator chip, stable Panel PCB Dimension: .3cm x 1.5cm Soil Probe Dimension: . 6cm x 3cm Cable Length: .21cm Interface Description(4-wire): VCC: 3.3V-5V GND: GND DO: digital output interface(0 and 1) AO: analog output interface Instructions for Use: Soil moisture module is most sensitive to the ambient humidity is generally used to detect the moisture content of the soil Module to reach the threshold value is set in the soil moisture, DO port output high, when the the soil humidity exceeds a set threshold value, the module D0 output low The digital output D0 can be connected directly with the microcontroller to detect high and low by the microcontroller to detect soil moisture The digital outputs DO shop relay module can directly drive the buzzer module, which can form a soil moisture alarm equipment Analog output AO and AD module connected through the AD converter, you can precise values of soil moisture Package Contents: 4 x Soil Hygrometer Detection Module Note: cable Random color, don't accept the specified color. 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 picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.