Koolertron Solar Power 2in1 29 keys Financial Accounting Portable Numeric Keyboard with Digital Display Calculator 29 Keys Number Keypad Compatible with Windows and OS X System This 2.4G mini wireless numeric keyboard have clear digital display, you can use it as ordinary calculator,and also display status when you connect it to the computer. 29 grids keys design,the size of keys are perfect suitable for office.Support Backspace and Tab button that provide more convenience. Special designed PC/CAL fuction toggle key that can chage it as wireless numeric keyboard or caculator freely. Solar power (must in the sunlight) so that users don't need battery when ONLY use it as calculator. While if you need to use it as a numeric keyboard,it must install 2AAA battery(not include in the package). When install battery,you can press"CONNECT" key to connect it to the computer,then you can press"SEND"key to send the calculate result to PC. Includes one 2.4G wireless numeric keyboard and one wireless usb receiver.The protection film paste on the LCD display.