INTERFACE : USB SYSTEM REQUIREMENTS : Win based computer : Win XP or Win Vista; USB Port Mac computer : Mac OS X 10.3.9 or later; USB Port * Hyper-fast scrolling lets user fly through long documents and Web pages with just a flick of a nearly frictionless scroll wheel * 1000 dpi laser precision outperforms optical mice * Experience smoother cursor control on virtually any surface * Soft side grips and a contoured design give user more support & control * Backward/Forward buttons let user move through Web pages and navigate their photo albums with ease * Plug-and-play