3 sensors for simple measurement of moisture content in soil and sphagnum moss

This is a new item purchased from overseas and was used for Platycerium (Staghorn Fern).
This is a simple sensor to determine the internal moisture level when inserted into a pot or sphagnum moss.
When you press the button, green indicates a moist condition, and red indicates a dry condition.
One button battery is included.
Thank you.