Logitech Wireless Number Pad N305 (Unifying - U) Logitech® Wireless Number Pad N305 gives you reliable, convenient number entry for notebooks. You won't worry about changing batteries every few months or unplugging receivers when you move around thanks to the three years of battery life* and a wireless receiver that stays in your notebook. Instead you'll be ready to crunch numbers-wherever and whenever. Plus, a powerful 2.4 GHz wireless connection and sturdy, portable design mean you can work co