Green Science - Potato Clock Be a scientist as you discover how to power this digital clock using potatoes. Experiment to find out what other substances will power the clock - you'll be amazed, Caution, High Voltage Inspiration and Fun. The Potato Clock allows you to generate enough electricity to run a digital clock using potatoes. Just push the zinc and copper electrodes into the potatoes causing an oxidation or reduction reaction that is converted to low voltage. Watch your child's delight and sense of accomplishment with the clock they create. Features: - Digital clock with cables - 2 cups - Transparent tape - Copper and zinc strips - A Cable - No batteries required - Detailed instructions What's in the box Digital clock with cables Transparent tape Copper and zinc strips A cable Instructions