A watch for the blind

How would you tell the difference between am and pm

how exactly does this work?

Or you could just take the glass off a normal analog wristwatch..

Most of the visually impaired people I know from FSDB have watches that talk or ones where the crystal flips up and they can touch the hands. The hands and numbers are heavier duty than a regular watch. I would think that this particular watch would get confusing particularly with little variation in the numbers.