This kit includes a digital clock zinc and copper strips a number of wires; three potatoes are all that's needed to create a working clock.No batteries required. Application: intellectual development hands-on brain interest training parent-child communication interactive toys. Manufacturered by Maxmoral. Operating steps: First kneading the fruit to make it more loose so that the water flow more fast plug in the two electrodes connect the wire install the diode or electronic clock on it. Warm prompt: There are some smaller parts Prevent the child from swallowing. Suggestion ageover eight years of age. Apple orange pineapple potatoes etc. can be made into fruit battery.