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! Real science & real fun the two 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/reduction reaction that is converted to low voltage. Watch your child's delight and sense of accomplishment with the clock they create. 4m potato-powered clock contains digital clock with wires, pots, connecting wire, transparent tapes, copper and zinc strips and detailed instructions. Does not include potatoes. Recommended for ages 7 and up. The potato clock uses a pair of ordinary spuds to power a digital clock. This kit includes a digital clock, wires and prongs; two potatoes are all that's needed to create a working clock. This kit is ideal for young science enthusiasts, and offers a valuable lesson on the transformative power of green science. No batteries required. Recommended for ages 8 and up.  # Pieces In Set: 7 Number of Batteries: 1 Recommended Ages: 8 Years And Up Measurements: 6.75 Length/Inches Assembly: Assembled Base Material: 100% Plastic Battery Size: 12 Volt Care: Wipe Clean Country of Origin: Imported p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 15.0px Calibri; -webkit-text-stroke: #000000} span.s1 {font-kerning: none} WARNING: CHOKING HAZARD – small parts. Not for children under 3 years.