Genius XScroll G5 PS/2 Optical Mouse, Black Enhanced precision with optical engine, eliminates moving parts and dust accumulation Original patent owner (US Patent No. 5,530,455) Suites for left - & right-handed use Connects to PS/2-port Interface: PS/2 800dpi optical three buttons & scrolling wheel for left- and right-handed use system requirements: Windows 9x/ 2000/ NT/ ME/ XP