Wireless mouse features darkfield laser tracking technology to provide accurate, precise cursor control on virtually any surface. Unifying receiver lets you add another compatible wireless mouse or keyboard (sold separately) without the hassle of using multiple USB receivers. Compact, ergonomic design helps keep you comfortable wherever you want to use your laptop. Click-to-click scrolling gives you the precision you need to easily navigate through lists, slides and images. With integrated thumb buttons, you'll move quickly backward or forward through Web pages and within applications. Advanced 2.4 GHz wireless technology delivers the reliability of a cord with cordless freedom for fast data transmission and virtually no delays.