29 pieces, 5 corners and a difficulty level of 10. : r/Jigsawpuzzles
Buy Clear Brain Teaser Impossible Puzzle -by NVP Puzzles- The Most Difficult Clear Puzzle Level 10 You Will Attempt. Great for Hours of Family Fun, Hard Brain Teaser Puzzles for Adults. Made
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Amazon.com: Yuu Asaka Ice Jigsaw Puzzle 9 - Level 10 - Extremely Hard : Toys & Games
The world's most difficult 9 Piece Puzzle!! - Level 10 Difficulty!! - YouTube
The world's most difficult 9 Piece Puzzle!! - Level 10 Difficulty!! - YouTube
PuzzleMad: A Frustrating Week Finally Ends in Some Happiness
Amazon.com: Yuu Asaka Ice Jigsaw Puzzle 9 - Level 10 - Extremely Hard : Toys & Games