Dimart 3 in 1 Soil Moisture Meter for Gardening/Farming, Display pH Acidity & Sunlight Testing Usage (Green) Soil Level: measure soil's moisture, pH and light by just plugging in the probe. Easy to read moisture, pH and light levels; promote plants' healthy growth. No batteries or electricity needed, just plug and read. Let you know your soil: when to water, control pH level, determine if plant is getting adequate light. Compact and portable design for indoor/ outdoor use. Convenient and no need battery.