Tender Toys Potato Clock fun with science thinking game The steel strips and potato form a simple battery that generates electricity to operate the clock. Each potato acts as a device called an electrochemical cell. It converts the chemical energy stored in the strips into electrical energy. Two potatoes are needed to make electricity strong enough to run the clock. This game is ideal for young science enthusiasts and offers a valuable lesson about the transforming power of green science. Specifications: Colour: green Gender: junior Material: plastic, steel Number of players: 1 to 5 players Duration: 25 minutes Age: from 6 years old