The rarely-seen Sound & Displays control panel is only for the use of the first-release Power Macintosh 7200, 7500, 8500 and 9500 computers. It debuted with the equally rare Mac OS 7.5.2. The design is confusing. Four panes represent sound input and output, as well as video and displays (video input and output, respectively). System sound is covered in a separate window. It merges the Monitors control panel and the Sound control panel into one, but does it in a less organised manner. It was replaced as of Mac OS 7.5.3 by the easier-to-understand Monitors & Sound control panel.