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.