MARBLE Hanayama Cast Metal Brain Teaser Puzzle OBJECT: Separate the center ball (which splits into two pieces) from the frame it sits in. Level 4 Difficulty (where level 1 is easier and level 6 most difficult). Your experience could differ. Small, compact, cast metal, beatifully designed brain teaser puzzle. Guaranteed to sharpen your skills at taking things apart and putting them back together Recommended for ages 12 through adult. (Some very bright 8 to 11 year olds may also enjoy.)