Features: 1) Display: touch LCD screen, 63 x 53mm; with backlights 2) Game functions: a) 3 levels of difficulty b) Helpful hints c) Auto-solve function 3) Function keys: On / Off key 4) Power supply: 2AAA alkaline batteries (not included) 5) Rules: fill in the grid so that every row, every column, and every 3 x 3 box contains digits from 1 to 9, and there is no any repeat number for each row and column 6) As the hottest puzzle since the Rubiks Cube 7) Studies show that playing Sudoku can improve memory, mind clarity, and even stop and prevent brain illnesses such as Alzheimer 8) Full LCD touch pad screen with stylus 9) Over 100,000pcs built-in puzzle games 10) With sound effect 11) Fits for your pocket and palm of your hand 12) Dimensions: 12 x 7.8 x 1.7cm 13) With LED backlight 14) LCD display: 63 x 53mm Optional packing: 1) Color box packing 60pcs/ctn Carton dimensions: 46 x 35 x 26.5cm N.W.: 9.5kg G.W.: 10.5kg 2) Clam shell packing 80pcs/ctn Carton dimensions: 38.5 x 32 x 24cm N.W.: 10.5kg G.W.: 11.5kg Conveyance: Qty/20\'\' FCL: 43,860pcs