Iomega Zip drives

Still handy today for small files if you don't want to use USB sticks:
https://en.wikipedia.org/wiki/Zip_drive

" Zip disks must be used in a drive with an equal or greater storage capacity. Higher-capacity drives can read lower-capacity media. The 250 MB drive writes much more slowly to 100 MB disks than the 100 MB drive,... They can be formatted in any version of Windows as normal... The 750 MB drive has read-only support for 100 MB disks."

" Sales of Zip drives and disks declined steadily from 1999 to 2003.^[10] Zip disks had a relatively high cost per megabyte compared to the falling costs of then-new CD-R and CD-RW discs."

"... during their prime, Zip disks greatly eased the exchange of files that were too big to fit into a standard 3+1⁄2-inch floppy or an email attachment, and there was no high-speed connection to transfer the file to the recipient."