It’s the guts of 3.5" floppies, like these, they usually stored 720kB, then 1.44MB, but the latest versions (double sided) were 2.88MB.

The larger one at the bottom is from a 5 1/4" (orange in this picture, the bug daddy in the picture is 8", first type I used, with COBOL)

… and now you kids know where the “save” button icon came from.

Started with the 8" bastards on a dedicated word processor (with a 12" CRT, green phospher glow, and typwriter style printer built right into the top of the unit!) that my dad had for medical filekeeping at his office.

It’s been amazing watching storage tech from those to zip drives, and now, floppies of any kind are dying.

My daughter found a 3.5" floppy in a drawer a couple of years ago (she was 20) and went “What is this? It looks just like a ‘Save’ button!” :)