THREE-YEAR BATTERY LIFE - Up to three years of battery life helps you save time, money, and the planet by practically eliminating the need to change batteries - An indicator light lets you know when the battery is low HYPER-FAST SCROLLING - Youll 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 PRECISE CURSOR CONTROL - Logitech optical tracking offers precise cursor control and smooth navigation on most surfaces with 1000 dpi ADDITIONAL BUTTONS - Want to quickly switch from page to page on the Web in an instant ? - Youll save time with the Forward/Backward buttons SCULPTED, RIGHT-HAND DESIGN - The sculpted, right-hand shape guides your hand to a naturally poised position and places customizable control within your reach Specifications - Sensor technology: High Precision Optical Tracking - Sensor Resolution: 1000 - Number of buttons: 7 - Scroll Wheel: Yes (with Hyper-Fast Scrolling) - Tilt scroll function: Yes - Battery life: 36-month battery life - Battery type: 2 AA batteries - Wireless operating distance: Approx 10m - Wireless technology: Advanced 2.4 GHz wireless connectivity(Unifying supported) - Interface: USB receiver