All-day comfort & scrolling come together in the Orbit Trackball with Scroll Ring. Award-winning Scroll Ring lets you scan up & down pages with ease. Medium 40 mm ball is designed as a perfect sphere to provide exceptional precision. KensingtonWorks software lets you customize the two buttons, adjust cursor & scrolling speed. Optical tracking technology for superior cursor control & accuracy. Detachable wrist rest supports hand & wrist for ergonomic comfort. Ambidextrous design works equally well for both right-handed & left-handed users. Plug & Play installation via wired USB connection. PC & Mac compatible. Connector / Port / Interface: USB 2.0; Left / Right Hand Use: Left / Right; Mouse Technology: Optical; Wired / Wireless: Wired.