This Meter checks moisture or PH level of the soil for the plant life. And more it can be helpful to keep your plants ever green & healthy. Its self-powered and no battery needed. Its also easy to be used either indoors or outdoors. You can just insert its probe tube in the tested soil at depth of 5cm approx. for about one minute after strongly scratching and cleaning the probe tip & tube with fine sandpaper. And then directly reading the value on the meter to identify the soil condition available for plant life.