Bepuzzled |Delta Hanayama Metal Brainteaser Puzzle Mensa Rated Level 3, For Ages 12 And UpHanayama's Delta brainteaser consists of three identical, interlocking pieces that are fiendishly hard to separate. As you begin to work with the elegant, symmetrical puzzle, you'll get glimpses of the inner layers. Still, you'll have to use all your skill to solve it. Once you've separated the pieces, can you put them together again? This 4. 72'' x 2. 99'' x 1. 811'' cast metal puzzle designed by Kyoo Wong is considered difficulty level 3 (moderate).