The Targus USB-PS/2Optical Mini Mouse is one of the world's smallest optical screen scroller mice, making it perfect for the road warrior who needs to save space. Unlike a traditional mouse, this USB-PS/2 Optical Mouse doesn't use a tracking ball. Instead, it uses an optical sensor and a digital signal processor to read and follow your mouse moves, eliminating erratic cursor movement. Using the "Screen-Scroller" wheel, you can scroll up, down, left or right and alternate between open applications. This optical mouse comes with a standard USB connection for true "plug and play" functionality. The optical mouse also comes with a USB to PS/2 adapter for compatibility with windows 98, 2000 and NT. On the plane or in the office, this is the perfect mouse.