Dual wireless connectivity offers the flexibility of 2.4GHz and Bluetooth (3.0 and LE), with 128-bit AES government-grade encryption security. The scroll ring lets you spin the dial to move up and down web pages or documents with complete ease. And the 40mm balls hard surface is specially designed as a perfect sphere for precise tracking and control. Four DPI settings let you easily adjust the cursor speed to fit your needs by selecting the appropriate level (400, 800, 1,200 or 1,600) - lower DPI for precision editing, and higher DPI for word processing or casual browsing. Ambidextrous design works equally well for right-handed and left-handed users. Trackball reduces wrist and hand movement to ease repetitive-stress injuries. Free KensingtonWorksdownloadable software provides a personalised experience, giving you the ability to assign a variety of functions (including shortcuts) to the buttons and adjust cursor and scrolling speed. Optical tracking technology delivers precise curso