The first floppy disks, invented and made by IBM, had a disk diameter of 8 inches (203.2 mm).[1] Subsequently the 5¼-inch and then the 3½-inch became a ubiquitous form of data storage and transfer into the first years of the 21st century.[2] 3½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for 5¼-inch, 8-inch, and other-size floppy disks are rare to non-existent. Some individuals and organizations continue to use older equipment to read or transfer data from floppy disks.