I do not know the actual name of this small Taytelbaum item, and I do not have the instructions. Similar items were made by other so the serious collector will know the handling.
A clear Plexiglass strip is inserted into a small square holder blocking off the slot in the square. Yet a small coin seemingly is able to pass thru the plexiglass strip which protrudes on either side,
The blue square measures approx. 1.5″ x 1.25″
The original small coins from the Netherlands are included but many others can be used.