Dual Power Calculator: Solar energy and battery backup power keep the desktop calculator working in low light conditions (not including AA batteries) : The electronic desktop calculator adopts a scientific large button design, which conforms to human habits and is comfortable to Contact. Desk Calculator Large Display: 12 digits display and large numbers , easy to use. Basic Calculator - Add, subtract, multiply, divide, backspace, % and . Auto-off when you do not use it about 10 minutes NOTE: Some user may use desk calculator in the early morning or night. The screen maybe difficult to read in low light without battery power. Please insert AA battery for continuous and accurate usage. Colour: as shown Material: ABS Size: 193 x 145 x 40MM Package Contents: 1 x Calculator Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.