Accurately measures white, yellow, pink and green gold, along with platinum, in a full range to 24 karat. Accurate to the nearest karat in the 6 to 18 karat range, plus 20, 22 and 24 karat readings. Ecologically safe with no dangerous acids or messy, harmful chemicals. Measures 12" x 9" x 1-3/4". UL listed. Three year warranty. Also operates using two 9 volt batteries (not included). 110 Volt