Logitech Marathon Mouse M705 uses less than half the power of comparable wireless mice. It's so energy efficient, one set of included AA batteries gives you up to 3 years of dependable power without battery changes. The sculpted, right-hand shape guides your hand to a naturally comfortable position. Plus, three integrated thumb buttons are right where you need them to move more quickly between web pages and applications. The tiny Logitech One tiny Unifying receiver stays in your notebook and connects up to six compatible devices in different places. A single spin of the scroll wheel helps you fly through long documents, presentations and web pages to find what you need in a flash. Or you can shift to click-by-click mode for precise line-by-line navigation of lists, slides or images. Laser tracking delivers smooth, responsive, precise cursor control on surfaces that cause problems for standard optical mice. Compatible with Windows XP, Windows Vista, Windows 7, Mac OS X 10.4 or later.