Optical tracking for superior cursor controlUnique touch scrolling ?? simply slide your finger around the outer ring of the trackball for effortless scrolling through web pages and long documentsFree downloadable KensingtonWorks software provides button customizationAmbidextrous designCompatible with all Windows, macOS, and Chrome (OS 44 and later) computersPlug-and-play, no drivers required2. 4 GHz wireless with nano USB receiver that stowes inside the trackball when not in use