Feature:1. FUNCTION: Multi function calculator not only has 4 standard arithmetic functions, but also supports percentage, memory subtraction and addition, memory clear and recall.2. LCD SCREEN: 12 bit digital clear display large digital LCD screen, easy to read from a distance, easy to use, beautiful.3. INCREASE PRESSURE SENSITIVITY: Calculators desktop adopts scientific design of large buttons, ergonomic design, increase pressure sensitivity, comfortable to touch.4. DUAL POWER SUPPLY: Calculator is powered by dual power supply using solar energy and built in battery, easy to operate, suitable for office and home use.5. SAFE MATERIAL: Calculator is made of wood material, safe and eco friendly, the numbers are engraved on the wood, 29 buttons, will not disappear after long time use.Specification:Item Type: Solar Powered CalculatorMaterial: WoodenNumber of Keys: 29 KeysProduction Process: CarvingWorking Current: 1.5AOperating Current: 4μABattery Type: 300mAh Li Ion Battery (Ship with Inbuilt Battery).Package List:1 xCalculator (Ship with Inbuilt Battery)1 x User Manual