The MX518 features an eight button design; you can click the primary buttons, the scroll wheel, the front/back buttons on the side, a button in front of the wheel, or the two behind it. The three buttons that people who do not use Logitech mice may not be used to are the three surrounding the wheel. The one closest to the user is an application switch, which is the same as the ALT-Tab command. The two closest to the wheel are this mouse's new feature. These two buttons are an on-the-fly sensitivity adjustment. This mouse is capable of 1600 dpi but pressing one of these the user can toggle its dpi to make the mouse more or less sensitive. This means that you can set the mouse to run at anyway between 400 and 1600 dpi and you can do so without having to enter any program or even stop gaming. This is the feature that has replaced the Cruise Control, and gamers should be happy to make the trade.