This extension allows your Mac to mount and read CD-ROMs. You will need it if you have a computer with a CD-ROM drive and want to use it. If you aren't using the CD-ROM drive with this set of extensions, feel free to disable it for a few K of extra RAM. Note that this extension doesn't work with non-Apple drives. Unnecessary if you do not have CD-ROM drive. Replaced by Apple CD/DVD Driver in Mac OS 8.5.