The Westgear M-250 USB Portable Mouse encompasses an ergonomic design with sculptured side panels that conform to your fingers. Its ultra lightweight helps alleviate any strain you may encounter with larger heavier mice. The integrated scroll wheel with click-to-click scrolling simplifies document and web browsing. With selectable DPI settings of 800/1000/1600, you can customize the amount of sensitivity that best fits your personal needs. As with all Westgear"s mice there is no software to install. It also comes in a choice of five trim colors to match your décor and personality. Product Specifications:USB Connectivity800/1000/1600 Adjustable Function Front/Back Button Function Enhanced Optical Sensor Metallic Color Accents4ft USB Cable Product Dimensions: Length: 2.4inWidth: 1.3inHeight: 3.9inWeight: 87.1g