7 buttons. Up to three years of battery life helps you save time, money, and the planet by practically eliminating the need to change batteries. The tiny wireless receiver stays in your notebook, so there's no need to unplug it when you move around. You'll fly through documents and Web pages with a single spin. Click-to-click scrolling gives you the precision you need when navigating lists, slides, and images. Laser grade precision means you'll enjoy smoother tracking on just about any surface. The sculpted, right-hand shape guides your hand to a naturally poised position and places customizable control within your reach. USB. Sold by each. Black.