The 3-in-1 Soil Moisture Meter ensures the health and quality of your plants by helping you know when to water, control pH level and light. To use stick the probe 2-4 inches into the soil and adjust until the dial swings. After 10 minutes note the moisture/pH/light level in the dial. Remove and wipe clean after use. 3-in-1: tests moisture, pH value and light level using two 20cm probe and a light sensor with three calibration tables for high accuracy and response Good for indoor or outdoor use No battery needed Helps prevent over watering