KKmall 3-in-1 Soil Meter with Moisture Light and PH Test Function Soil Level: Measure soil moisture, pH and light by just plugging in the probe. Scientifically Accurate: Easy to read moisture, ph and light levels, promotes healthy plants. No Battery Needed. GOT SOIL DATA:when to watering, control PH level, determine if plant getting adequate light. Good ideal for promoting the plant growth both outdoor and indoor.