Kensington Notebook Keypad/Calculator with USB Hub, 19-Key Pad 72274 3-in-1 design: use as a fully functional calculator or a 19-key pad for data entry or a USB hub Integrated USB hub has 2 USB ports for your extra work accessories Quickly switch between keypad and calculator with a simple press of the mode button Clear LCD display works in various lighting conditions No software needed, just plug it in to use