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 Calculator Material: Wooden Number of Keys: 29 Keys Production Process: Carving Working Current: 1.5A Operating Current: 4μA Battery Type: 300mAh Li Ion Battery (Ship with Inbuilt Battery). Package List: 1 x Calculator (Ship with Inbuilt Battery)1 x User Manual