Logitech 910-005931 USB Unifying Receiver

 — Universal: Easily connect up to 6 compatible Logitech keyboards and computer mice to one laptop – without the hassle of multiple USB receivers, on Windowas as well as on Mac
— Powerful, reliable, wireless connection: Connect up to 10 metres (33 feet) away with virtually no delays or dropouts between your cordless PC mouse, keyboard and computer
— Unifying Receiver: You can leave the mini-receiver in your notebook, so there’s no need to unplug it when you move around
— Multi-Device: With your Unifying receiver plugged into your laptop or Macbook, use it with a wireless ergonomic verticle mouse or trackball in the office, and with your optical gaming mouse and keyboard at home