Wireless Mouse M317 with Unifying Receiver &ndash; Black Contoured design: Comfortable shape with soft side grips Logitech Advanced Optical Tracking: Enjoy point-and-click precision and smooth scrolling Unifying Receiver: Robust wireless connection with one tiny USB receiver that stays in your laptop Long battery life: Up to 12 months of battery life virtually eliminates the need to change batteries Wide compatibility: Works with Windows, Mac and Linux computers