Detailed Product Description- Endless generate and supply literal 9x9 Sudoku puzzles. 
- Minimum size 43x73x15mm. 
- Keep a Sudoku into your pocket. 
- 
Keychain hook or hanging hook. 
- Built-in three levels, easy, hard and harder. Suit for any level people. 
- User levels: Create your own Sudoku or input from newspaper or book. 
- Integrated Sudoku solver. Can solve million true unique Sudoku. 
- Advance hint system: Provides a step solution, error location or solve completely. 
- Save and load up to 2 games. 
- Count up or Count down in minute. 
- Count up or Count error input. 
- 
Clock and 
Alarm. 
- includes 1xCR2032 battery 
- free download PC sudoku