The Moissanite tester is used to distinguish rough diamond from Moissanite. It can differentiate diamond and Moissanite fleetly by showing two kinds of colors. It is recommended to be used after positive testing result for diamond. Features: 1.Accurate, compact and portable. 2.kinds of LED colors indicate testing result. 3.Use DC 9V, 6F22 battery. 4.Limited three year warranty.