yes they are. the reason is the inside not the outside. the inside is a flimsy piece of what looks like vinyl. kinda like a small thin floppy version of a record.
FWIW, when I was a boy, floppies came in two sizes, the 8-inch floppy disks and the 5 1/4-inch mini-floppy diskettes, which came in single-sided and double sided. I use to use a hole-punch to make my floppies into flippies.
Did it with a sharp knife to get rectangled holes for that. Easier than deleting the disks is reformatting them to 'the other' format then by using adhesive tape.