The Mizar "Diamond Detective" state-of-the-art tester is simple but precise, giving the user a quick true/false reading. Housed in a high impact plastic case, it is everything one needs to test diamonds in rapid succession, whether mounted or unmounted. No external power cords or clips necessary, this diamond tester uses a 9V battery. Full two year warranty included. Features: Metal alert (a long beep when user accidentally touches metal rather than stone) Large/small switch for testing diamonds over and under 8 points Diamond indicator (a green light), which illuminates if the stone is a diamond 7 second warm-up time with a 150 second shut off alarm Comes with complete instructions 2 year warranty except for the battery and tip damage Low battery indicator 9 volt battery included Note: The Mizar Diamond Detective, like any thermal conductivity tester, cannot detect Synthetic Moissanite.