Quadra Monitors Extension is an extension for use with Macintosh Quadra computers. It is mainly a bug fix which prevents the colors on monitors attached to Quadras from being confused and messed up. The extension describes the capabilities of the built-in video card for the Macintosh Quadra and Macintosh Centris computers. If this file is removed, monitor options (such as gamma settings) may not be available, although you can still use the video card with your Mac and you can still switch between different numbers of colors displayed on your monitor.