Multi function financial Accounting 2.4G wireless 29 Key numeric keypad for Tablet or Laptop Color Black Wireless transmission is very convenient to use,Wireless receiver Plug and Play Whenever and wherever,Is compact and comfortable to use , easy to carry numeric keypad , allowing you to deal with more professional digital The numeric keypad can independently use,press PC/CAL button to switch,and support backspace button,Compact and portable, rugged design System Requirements: IOS, Windows XP, Windows Vista or Windows 7, USB port Key Mechanical working life: The keycaps life of more than 10 million times;Operating Current : 5mA (MAX) Sleep Current : 0.5mA Effective Distance: Approximately 32.8FT Accessibility