The Adesso iMouse S8 - USB retractable Mini mouse is the perfect travel companion while on the road and the perfect desktop mouse when you return our innovative design features a built-in scroll wheel to enable you to scroll up or down with pinpoint accuracy and control A retractable USB cable allows you to expand and collapse the cable for improved mobility Its built-in DPI of 800/1200/1600 and Optical sensor lets you navigate your cursor with better speed accuracy and reliability on almost all surfaces