Designed for how you use the Web,* our newest micro-precise scrolling makes reading your Facebook, shopping Amazon or scrolling through Google searches easier. Plus, tilting the wheel moves you backward or forward on the Web.** * Designed to improve your online experience, the wheel also helps perfect scrolling when you're using other applications, such as Microsoft Office or Adobe PDF. ** Tilt wheel will not support backward/forward on Mac computers but will support Dashboard, Expos or Spaces (when you select in System Preferences). Based on the best-selling shape in the world, it keeps your hand happy-even after long hours of use-thanks to its contoured shape and textured rubber grips.* * Based on independent sales data (in US$ currency) for CA, US, AU, FR, DE, IT, from September 2008 through August 2010. With up to 18 months of battery life, it virtually eliminates the hassle of changing batteries. Smart sleep mode saves power, while an indicator light eliminates surprises.* * Battery life may vary based on user and computing conditions. The tiny Logitech Unifying Nano-receiver stays in your laptop-so it's less likely to be lost-and gives you a reliable connection with virtually no delays or dropouts. Plus, you can easily add compatible wireless devices to the same receiver. At home, at school, at work- forget about tricky finger maneuvers with your laptop touchpad. Enjoy precise clicking and pointing while navigating your favorite websites thanks to Logitech Advanced Optical Tracking.