• Just like the Contour Mouse, the PMO5 mouse gives your hand support from underneath. A specifically designed arch fills the hollow of your palm and allows you to rest your hand on top of the mouse. This promotes straight alignment of your hand and wrist while slightly elevating your wrist from the desk. • The PMO5 Mouse has elongated buttons that allow you to use the second knuckle of your finger to click. When you use this (instead of your fingertips), you use a stronger, thicker tendon with small, subtle motions and automatically avoid flexing your fingers. • Like the distinguished Contour Mouse, PMO5 offers a proper, full-size third mouse button, making middle clicking as easy and smooth as a regular click. The option of having a frequent command by a finger click is a smart feature for high-click-intensive tasks such as CAD/CAM and design applications • Your thumb rests naturally on the side along a pronounced groove on the PMO5, with a rocker switch (performs "back" and "forward" in most browsers) below it. • The PMO5 Mouse is available in four right-handed and one left-handed versions. When you find the size that truly fits your hand, you increase both comfort and control.Contour Design