Logitech Wireless Trackball M570
The sculpted shape supports your hand for comfortable control all day long. This trackball includes the Logitech Unifying receiver. The tiny wireless receiver stays in your laptop, so there's no need to unplug it when you move around. Plus, you can easily add a compatible keyboard, number pad or mouse without the hassle of multiple USB receivers. You can go for up to 18 months without changing batteries* - and, the convenient battery indicator helps to ensure that you'll never be caught off guard.