The hard pocket stone I found is not file size and is definitely not a
diamond stone.
it's the same size as the gummi stone (3' x 1' x 0.5' ). only
difference is that it's hard.
if I remember correctly , both the gummi stone and pocket say they're
for polishing and deburring.
hence the confusion.

what does it mean to deburr edges. do you actually rub the stone againt
the corner point of the edge?