Kensington Pro Fit Ergo Vertical Wired Trackball K75256WW

Ergonomist-approved design promotes proper wrist, arm, and shoulder alignment to maximize comfort and minimize potential strains.
Easy-to-use mouse-like shape reduces learning curve when transitioning from a mouse to a trackball.
Provides more accurate and smooth cursor control, and allows you to easily switch between DPI settings for different cursor speed control.
A secure wired connection means you’ll never worry about batteries or wireless interference.
Use the plug-and-play default settings, or download KensingtonWorks software to set pointer and scrolling options and professionally customize nine buttons to tackle common tasks with one touch.
Unique easy-to-clean design features a button to eject the trackball for easy cleaning.