Easy to use even for beginners the simple handheld testers have an LCD display, LED lights and emit audible sounds to give accurate readings time after time. Can distinguish diamond from white corundum and YAG.
Buzzer alerts you when the probe tip touches metal.
Real diamond are indicated by sound and light signal.

Specifications:

Power: DC 9V battery x 1
Weight: 106g

Features:

Powered by DC 9V battery x 1
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
If stone is a simulant such as cubic zirconium (CZ), nothing happens (except with synthetic moissanite).
Metal alert (a long beep when user accidentally touches metal rather than stone)
Large/small switch for testing diamonds over and under 8 points
Accessories:

DC 9V battery x 1 (included)
Leather Pouch Case