The A4TECH OP-330 is an optical mouse with hyper-fast scrolling for increased productivity. It has a nearly wider scroll wheel that lets you fly through long documents and Web pages with a single flick. You can experience smoother cursor control on virtually any surface thanks to the 1200 DPI. It has a contoured design that gives you more support and control. It offers extreme quality, over 5 million clicks guaranteed. The dust-resistant design prolongs the wheel's lifespan. The OP-330 offers 8 gestures to perform selectable hotkey commands. The 4-way Wheel enables you to perform smart horizontal & vertical scrolling. The A4TECH OP-330 comes with a 1-year warranty.