The 3Dconnexion CadMouse allows you to design structures and devices on your computer like any professional CAD designer. The ergonomic design supports your hand during design and ensures it stays in a natural position. The middle mouse button serves as a replacement for a scroll wheel. Use the middle mouse button to scroll through your design. Prefer to use a scroll wheel? No problem, you can still use one. QuickZoom also allows you to quickly zoom into a specific part of your design at the touch of a button. In order to use QuickZoom, you should press the 2 buttons on the side of the mouse.