Everyday casual, Back Pocketa" Sudoku combines a stylish and portable package with 100 Sudoku puzzles in 3 difficulty levelsa "perfect for the every-day-is-jean-day man who enjoys challenging his smarts. The Posh and Pocket PoshA(R) puzzles series have over 3 million copies in print since their inception in May 2008. "Back Pocket Sudoku" offers 100 Sudoku puzzles featuring 3 levels of increasing difficulty protected by a rugged camouflage cover perfect for sport and military enthusiasts.