The Hanayama Hourglass puzzle is made by combining two pieces each of two similar, but slightly different shapes. They are carefully calculated, with tricky movement added. It is impossible to unravel with one linear movement. Designed by Korean puzzle creator JinHoo Ahn. Hanayama is known worldwide for challenging puzzles and quality manufacturing. Can you take the pieces apart, then put them back together again? Hanayama cast metal brain teasers have 6 levels of difficulty, and each puzzle is Mensa-rated. Level 6 puzzles are considered extremely difficult by most puzzlers. Recommended for 1 player, ages 12 and up. Made in China. Package dimensions: 4.750 x 3.000 x 1.750 inches. 4 pieces. Includes 1 Puzzle. Wipe clean with dry or damp cloth. Imported Material & Care Plastic Spot clean only