5 inch

A floppy disk, also known as a floppy, diskette, or simply disk, is a type of disk storage composed of a disk of thin and flexible magnetic storage medium, sealed in a rectangular plastic enclosure lined with fabric that removes dust particles. Floppy disks are read and written by a floppy disk drive (FDD).
Floppy disks, initially as 8-inch (203 mm) media and later in 5 1⁄4-inch (133 mm) and 3 1⁄2 inch (90 mm) sizes, were a ubiquitous form of data storage and exchange from the mid-1970s into the first years of the 21st century. By 2006, computers were rarely manufactured with installed floppy disk drives; 3 1⁄2-inch floppy disks can be used with an external USB floppy disk drive, but USB drives for 5 1⁄4-inch, 8-inch, and non-standard diskettes are rare to non-existent. These formats are usually handled by older equipment.
The prevalence of floppy disks in late 20th century culture was such that many electronic and software programs continue to use save icons designed to look like floppy disks well into the 21st century, a commonly-cited example of skeuomorphism in user interface design. While floppy disk drives still have some limited uses, especially with legacy industrial computer equipment, they have been superseded by data storage methods with much greater capacity and transfer speeds, such as USB flash drives, memory cards, optical discs and storage available through computer networks such as cloud storage.

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