Tender Toys Potato Clock fun with science brain game The steel strips and potato form a simple battery that generates electricity to run 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 create enough electricity to run the clock. This game is ideal for young science enthusiasts and provides a valuable lesson in the transformative power of green science. Specifications: Color: green Gender: junior Material: plastic, steel Number of players: 1 to 5 players Playing time: 25 minutes Age: from 6 years