The Plant Pal Robin sings when your plant needs watering! A plant moisture alarm is a sophisticated electronic tool, housed inside the body of our "Plant Pal", to help you prevent over and under watering of your house plants. Just position the moisture-sensing probes into the soil. A light sensor prevents the Plant Pal from singing and waking you at night. Best of all, it is an attractive conversation piece that will enhance the beauty of your plant. Replaceable button cell battery included. Lasts for up to 1 year of monitoring.