Logitech M557 1000DPI 2.4GHz Ergonomic Wireless Bluetooth Mouse (Black)

1. The button behind the wheel button allows you to quickly and easily switch between the desktop and traditional Windows applications and the new interface of Windows 8 to full screen. 2. The 1000 dpi optical sensor and high definition provide smooth, uniform cursor control so that it can work accurately and reliably on various surfaces. 3. You can change the behavior of all buttons to suit your needs and preferences. Our powerful software can be used with Windows 8 versions of Windows and Mac OS. 4. Power supply mode: 2 x AA Battery(not included) 5. Roller direction: four-way roller