[2pack Soil Moisture Meter ] Dr.meter Hygrometer Moisture Sensor Meter for Garden, Farm, Lawn Plants Indoor & Outdoor(No Battery needed) This Soil Moisture Meter used for Soil PH test not for Water PH test. Measure soil's moisture content by just plugging in the probe Easy to read moisture levels, including ten scales No batteries or electricity needed, plug and read Color coded reading system, from red, green to blue Compact and portable design for indoor/outdoor use