Techno Source's best-selling original pocket-sized edition features more than 1 million puzzles, eight levels of difficulty to challenge logic skills, a tutorial mode for beginners and a notes feature. A Sudoku Solver lets users input puzzles from their favorite sources to solve or play. It is fully illuminated for play anytime, anywhere. Launch date: December 2005.
— According to Eric Levin, EVP, Techno Source, “Electronic games continue to be huge sellers this year, especially portable logic puzzles like Sudoku.  Techno Source’s line of electronic Sudokus was almost completely sold out this [2006] holiday shopping season and we experienced an incredible increase in sales of more than 150 percent from last year. ”