For your consideration, here is a Vintage USS Darter SSN-662 US Navy Submarine Tile Plaque. It is marked FM, made in Japan on the back. It measures 6 inches square. There is very little wear on it. It has a few smudge spots on the back of it. Item pictured is the actual item up for sale and comes from a non-smoking household. (215.769w-1.10bx)