Dual Wireless with 128-bit AES Encryption Security The flexibility of 2.4GHz and Bluetooth (3.0 and LE), with government-grade encryption. Scroll Ring and Medium Ball Spin the dial to move up and down web pages or documents with complete ease. The 40mm ball's hard surface is specially designed as a perfect sphere for precise tracking and control. Four DPI Settings Easily adjust the cursor speed to fit your needs by selecting the appropriate DPI 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. KensingtonWorks Customisation Free downloadable 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 cursor movement for superior accuracy, so you can get where you want on the screen quickly with less hand movement, improving productivity and efficiency. Detachable Wrist Rest Soft cushioning supports the hand and wrist in ergonomic comfort for pain-free productivity during extended periods of activity on the computer. Compatibility Works with Mac and PC.