HT-ZS11M - ZOpid Electronic Sudoku with Touch Screen and Back Light Four easy to learn and challenging mind games: SUDOKU, DIGIT BRICK, INSTANT MEMORY & MASTER MIND - Demo mode at the beginning of every game Digital touch screen - Large high-contrast LCD screen with soft-white backlight, which is easy on eyes and suitable for day or night use Game automatically enters sleep mode if not used for 3 minutes - Resume function continues game where it was when the game was turned off or went into sleep mode Undo function can undo up to last 128 steps - Uses 2 "AAA" batteries (not included) - Display size 2 X 2.5 inch Package Includes: Handheld game, Stylus and Instruction manual