The Canon AS-120 runs on both solar energy and battery power, so you'll never have to worry about your calculator dying while you're in the middle of important calculations. Just like many other Canon products, the AS-120 is also made of recycled materials. Because the calculator shuts off automatically after it hasn't been used for 7 minutes, it helps you save energy. The large, slightly tilted LCD display provides increased legibility. If you're looking for a reliable calculator, the Canon AS-120 is a great choice.