Ready to challenge your brainpower? Keep your brain sharp at all times with the No 4 In A Row puzzle book. It's a great logic puzzle game. It's ready for you! Details in this book : ✅ For Adults, Seniors, and Teens. ✅ 3 Grid Formats: 8x8, 9x9, and 10x10. ✅ 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.