Sudoku Keychain LDC Game (colors may vary)

After several attempts, I finally got a working tiny sudoku game on a keychain. Had to pry up the connections on the battery terminals though. Also no power button (has auto shutoff after a few minutes idle), but nice hint function. Not sure this is the same exact product as the Susan Vorderman one. Different color and no logo.

Of all those I have tried, this is the best truly pocketsized sudoku electronic game I've found. Can be a bit clunky at times but it does work consistently.