Let's challenge your Brain! Book features: Over 1,200 puzzles are Hard-level for adults. - Hours of fun and improve your brain activity. - Includes solutions for every puzzle at the end of the book in case you get stuck. - A good companion for morning coffee, your lunch break, a rainy Sunday, and vacations. - Normal size grids for 12 Puzzles per page. - Easy to tear out, thanks to wide margins - Great gift ideal for lovers of Sudoku