Micro-precision scroll wheel: Faster, easier web navigation plus advanced optical sensor for smooth tracking on more surfacesExtended battery life: Go for up to three years without a battery change. Takes 2 Double A batteries.Compact comfort in cool colors: Ergonomic shape, soft rubber grips and great style that's easy to take anywhereMulti-device wireless receiver: Tiny Unifying receiver connects up to six Unifying-compatible devicesFor Windows and Mac computers: Works with Windows XP, Vista, 7 and Mac OS X 10.5 or later
