The Scorpius 35 keyboard incorporates a full size desktop trackball to give you all the functions of a mouse without taking up any additional desktop space. The convenient trackball keeps your hand movement and efforts to a minimum for more comfortable and friendly feel. This is especially convenient when using Windows applications where there is heavy dependence on mouse cursor movement. Rated at 20 million cycles, the Scorpius 35's durable mechanical click key switches and the built-in trackball utilities the highest quality micro-switches.