This is an interesting puzzle in an attractive format. It was designed by famous Dutch puzzle designer Niek Neuwahl in the 1990's.
You are given 5 pcs that make a square, PLUS an extra small square piece. You goal is to remove the small square and place it into the tray with all the rest of the pieces! Looks impossible, but of course there is a way...
Made of wood and does not come with a cover.