You see tons of disk notchers / punch for 5 1/4″ floppy disk, but very few if any for 3 1/2
Back in the day a 5 1/4″ disk could double its capacity with a simple notch (Which would allow you to FLIP the disk in the drive)
However, 3 1/2″ disks came in 720K or 1.44MB, to let the drive know there was an HD 1.44MB disk inserted it would look for the extra hole.
As you can see from the images the notcher / punch is in great shape and 100% working!
Don’t miss your chance to own a rare piece of history!