The Kensington trackball legacy continues with the Orbit® Wireless Trackball with Scroll Ring. This trackball features a patented scroll ring that allows you to scroll up and down pages with ease, customisable buttons, dual wireless connectivity (2.4 GHz, Bluetooth 3.0 and LE) with 128-bit AES government-grade encryption security, four DPI settings (400, 800, 1,200, or 1,600) to easily adjust the cursor speed to fit your needs, a detachable wrist rest, ambidextrous design and plug-and-play ease for Mac or PC. - 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