Soil Meter, Soil Water Monitor, Humidity Plant Tester, 3-in-1 Soil Moisture Sensor for Light, PH Level Measurement for Growning Garden, Lawn, Farm, Plants, Flowers, Vegetable, Herbs & More

Simple design but works reliably. Zinc-copper cell battery + galvanometer + solar cell, triple in one. solar cell measures light intensity. Zinc-copper battery measures PH, and provides power for moisture meter. It's easy to find a moisture meter, but its hard to find such delicate design combine three in one.