Kensington Orbit Trackball Mouse with Scroll Ring (K72337US), 4 1/2X5 1/2X2"

Optical tracking technology provides 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; The blue 40mm ball has been specially designed with an absolute spherical, hard surface for precise tracking and control
Unique scroll Ring let you move up and down web pages or documents with ease; ambidextrous design works equally well for both right-handed and left-handed users
Detachable Wrist rest softly cushions and cradles the hand and wrist in an ergonomic position for pain-free productivity during extended periods of activity on the computer
Free downloadable KensingtonWorks software provides a personalized experience, giving you the ability to assign a wide variety of program functions to each of the 2 buttons, as well as adjusting cursor and scrolling speeds
ChromeOS user can get HID functions for a trackball but will not be able to customize their device through KensingtonWorks.