Nope, it doesn't say that, it says 1.4M and 720k PC disks.
It can write 1.4M Mac disks, but there is no such thing (as a standard) as a 720k Mac disk.
The DD disks were formatted using a different encoding and differing number of sectors per track depending on circumference.
You do need a set of 800k System 6.0.5 upwards disks which any other Mac owner can produce for you.
Yes you can put in most 50pin 2Gig or lower disks, but expect fun formatting it if it's not from Apple. I do know Mac Plusses can be very picky about what they boot from.