Your fingertips rest in a shallow groove on the buttons. This patented innovation secures the mouse in your hands and makes its movement much more precise. The ergonomic shape supports your hand in a handshake position. Since 2002, users have consistently reported that the Evoluent VerticalMouse offers excellent comfort and even alleviates their wrist pain. An extra-wide lip along the bottom edge prevents the last finger from rubbing against the desk. Skillfully placed thumb buttons are easily accessible both above and below a contoured thumb rest. A speed button behind the wheel allows for convenient adjustments without releasing your grip on the mouse. Up to four lights indicate pointer speeds from low to high. A laser sensor ensures reliable tracking on most surfaces. Configure the buttons so that nearly any desired function—such as copying or pasting—can be performed with fewer clicks and mouse movements. The sensitivity per notch varies dramatically depending on the speed at which you scroll the wheel—from slow and precise to hyper-speed for scrolling through long pages. Quickly reduce your screen brightness to lessen eye strain simply by turning the mouse wheel. Easily adjust the screen brightness as the ambient light changes.