Ready to challenge your brainpower? Keep your brain sharp at all times with the Sujiken 9x9 puzzle book. It's a great sudoku puzzle game. It's ready for you! Details in this book: ✅ For Adults, Seniors, and Teens. ✅ Grid Formats: 9x9. ✅ 3 Levels: Easy, Medium, and Hard. ✅ Total all 220 Puzzles. ✅ 148 Pages with full solution. ✅ Pocket Size: 4 x 6 Inches. ✅ Large font easy for reading. ✅ Economical and worthwhile.