Think about it. If you spend more than eight hours a day using your computer, you're spending more than eight hours a day using your mouse. Don't you want to be as comfortable as possible? Now, you can. As natural as a handshake. - Elegantly contoured shape: Fits your hand for maximum comfort. Designed to support the naturally curved shape of your hand. - Full-size design: Big. Broad. For support from your palm to your fingertips. One spin and you’ll never go back. - MicroGear™ Precision scroll wheel with hyper-fast scrolling: Lets you fly through long documents and Web pages with one spin. Or, shift to click-to-click mode to scroll through lists and photos. All the benefits of a cord with the convenience of cordless. - Logitech's advanced 2.4 GHz wireless: Dramatically reduces interference with 300 times faster data rate.* Virtually no delays or dropouts. You're in control. - Adjustable-dpi laser engine: Provides two smooth-tracking modes (up to 1600 dpi) for customizable precision. Choose the dpi setting that's right for you—from pixel-precise to ultra-fast for customizable precision. - Stealth thumb button: Makes it easy to jump from one program to the next. One of ten programmable buttons that put total control at your fingertips. - Extended battery life: Minimize the hassle of changing batteries with nine months of battery life. On/Off button saves even more power. Battery-indicator light eliminates surprises.