The Kensington Orbit Elite features a medium-sized silver ball that is operated by the finger tips, and two programmable buttons.You can choose what each button will do; carry–out a function or even pull down a personalised menu. By reducing the number of clicks you have to make you are less likely to develop RSI. Similalry if you already have RSI, the customisable settings of this mouse will enable you to better manage your injury.The trackball features highly precise optical technology offering optimum access and control of your computer.Features: