We are offering our customers an excellent quality range of Diamond Testers with High quality material, Easy to use even for beginners, LCD display, LED lights Emit audible sounds to give accurate reading, Diamond indicator (GREEN light ), which illuminates if the stone is a REAL diamond,If stone is Fake crystal, a simulant such as cubic zirconium ( CZ ), will be no reaction, Metal alert ( a long beep when user accidentally touches metal rather than stone ), Dimension: 16.5 x 4.5 x 2.5cm.