Japanese Construction Lock Puzzle - Puzzle For AdultComposed of 18 identical interlocking wooden sticks. Assembles into a large three dimensional square structure. Releasing the lock requires removing a single key piece. Collapse happens easily once the key piece is removed. Reassembling all 18 pieces is a rewarding engineering challenge. Precision cut pieces offer a smooth, tactile feel. High quality wood and craftsmanship for lasting durability. Doubles as an attractive art piece for desk or coffee