This electronic chess game was rated The Best due to its superior performance in evaluations by the Hammacher Schlemmer Institute. In comparison tests performed by the DePaul University chess club, this model was determined to have the most accurate skill levels and the most variety of time settings. The Best unit was also lauded for its clear and easy to read LED screen, its intuitive settings, and the high-quality construction of its board and pieces. Its superior features include illuminated squares for easy learning, an infinite number of difficulty levels, and seven language settings. Includes nine user books and an AC adapter. 15 1/2" L x 17" W x 1" H. (5 lbs.)