Six to twenty four karat range, state-of-the art electronic gold testing technology from Tri-Electronics. Technological breakthrough that allows for the measurement of low to high karat gold products, assuring the buyer of gold content in the most critical gold alloys. Measures 12" x 10" x 3" (305 x 254 x 76 mm). UL listed. Three year warranty. Also operates using two 9 volt batteries (not included).