PMC MicroMate floppy disk
The PMC MicroMate floppy disk was a 5 1/4" floppy used in the PMC MicroMate computer, which was made by a company (PMC: Personal Micro Computer) that was a subsidiary of Recortec (which still exists and makes server-rack computers and consoles) which previously made TRS-80-compatible computers. The MicroMate used the CP/M operating system, and could be attached to a terminal or a TRS-80 Model 100 depending on whether it was being used as a standalone computer or an accessory.
There were two native floppy formats designated as "Type A" and "Type B", and some other manufaturers' formats were also supported (but new disks could only be formatted in the two native formats). The native formats were double-sided/double-density, but some of the other formats supported were single-sided and/or single-density.