Hanayama cast puzzles are high-quality brain teasers made with cast metal and sure to trick your brain! They come in 6 challenging, Mensa-rated levels of difficulty, 1 being the easiest, and 6 being very difficult. The included booklet illustrates the challenge for each puzzle in the series, but please note that solutions are not provided in order for you to experience both the "fun" and "agony" of solving these puzzles. Level 4 difficulty is challenging.