Solar power with AA battery backup (battery not included), helps make sure that the calculator will function even in a dim place when the battery is installed. Durable plastic keys allow for constant use without wear and tear. Suitable for your business travel use. This easy-to-use calculator takes up little space on your desktop and fits into your briefcase or desk drawer. Great for home, office and on the go. Performs common math as well as various financial functions. Perfect for both business and students.