Model No.: BK-2003 Description: Diamond Tester: The Prestige Series II Diamond Tester with state-of-the-art technology assuring quick- accurate readings to determine if a stone is a real diamond or a fake. Features include: Automatic and manual mode. Linear display for increased information. Adjustable gain for small stone sizes. Compensation for ambient temperature. Fast warm up time Ten seconds! Portable with one nine-volt battery (included). Auto shut-off with a push button switch. Unique new anti-fade circuit which compensates for stone heating. Low battery indicator for accurate readings. Multipurpose alarms: A. Beeps when ready. B. Metal alert. C. Beeps repeatedly when testing a diamond.