Dual : Solar energy and battery backup keep the desktop calculator working in low light conditions (not including AA batteries)Desk Calculator Display: 12 digits display and numbers , easy to use.: The electronic desktop calculator adopts a scientific button design, which conforms to human habits and is comfortable to contact.Basic Calculator - Add, subtract, multiply, divide, backspace, % and MU. Auto-off when you do not use it about 10 minutesNOTE: Some user may use desk calculator in the early morning or night. The screen maybe difficult to read in low light without battery . Please AA battery for continuous and accurate usage.colour:BlackMaterial:plasticsize:15 x 12 x 42cmPackage Contents:1 x CalculatorOnly 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.