Zip Disk

From Mac Guides

A Zip Disk is a type of removable media disk created by Iomega that originally held up to 100 MB of data. Later, 250 MB and 750 MB sizes were introduced which were backward compatible. For example, the 750 MB drive can read both 100 MB and 250 MB disks as well as 750MB disks. However, a 200MB drive cannot read 750MB disks. Iomega Zip drives came internally in certain Macintosh G3 and G4 computers. Most Zip Drives were external SCSI drives, and later were USB.