Manufacturer: Logitech. The 3 year battery life (Battery life based on a calculation of an estimated 2 million keystrokes per year in an office environment. User experience may vary) means you won’t spend your time tracking down new batteries. An indicator light helps you keep an eye on your charge level. The tiny 2.4GHz receiver stays in your notebook giving you the reliability of a cord plus cordless convenience and freedom, it provides fast data transmission with virtually no delays or dropouts, and 128-bit AES encryption. Plus, you can easily add compatible mice and keyboards. This sturdy number entry-solution is easy to take with you, so you can work confidently and quickly, just plug the receiver into a USB port and start crunching numbers right away. Package Contents includes Number Pad, Logitech Unifying receiver, User documentation and two AAA batteries.