Logitech Wireless Number Pad N305 gives you reliable, convenient number entry for laptops. You wont worry about changing batteries every few months or unplugging receivers when you move around thanks to the three years of battery life* & a wireless receiver that stays in your laptop. Instead youll be ready to crunch numbers – wherever & whenever. Plus, a powerful 2.4 GHz wireless connection & sturdy, portable design mean you can work confidently & quickly. Its easy to get started – just plug the receiver into a USB (Universal Serial Bus) port & Number Pad N305 is ready right away (additional features are available through an optional software installation). * Battery life may vary based on user & computing conditions. Youll get up to three years of battery life*, which practically eliminates the need to change batteries, as well as the hassle, expense & waste that go with it. An indicator light helps you keep an eye on your charge level. The tiny, Logitech Unifying receiver stays in your laptop. Theres no need to unplug it when you move around, so theres less worry of it being broken or lost. & you can easily add compatible wireless mice & keyboards to the same wireless receiver. Logitech Advanced 2.4 GHz wireless connectivity gives you the reliability of a cord plus cordless convenience & freedom – fast data transmission, virtually no delays or dropouts & 128-bit AES encryption. The solid, portable design makes Logitech Wireless Number Pad N305 a sturdy number-entry solution thats easy to take with you. When you need to run numbers on the road, you can work confidently & quickly – wherever & whenever. Simple setup makes it easy to get started – just plug the receiver into a USB (Universal Serial Bus) port & start crunching numbers right away (additional features are available through an optional software installation).