Information about this product Product from unclaimed amazon package. PROFESSIONAL DIAMONDS MEASUREMENT Professional diamond tester Diamond Selector II is an intuitive, reliable device with a clear display. Now you can easily and quickly distinguish diamonds from imitations and other stones, regardless of whether they are raw, cut or mounted. The tester uses the measurement of thermal conductivity as a method, thanks to which it will distinguish a real diamond from its imitation. The device is equipped with a battery charge indicator ( you can be sure that you always measure with a charged device ) and an "automatic switch-off" system that automatically turns off the tester after approx. 1.5 minutes The tester has a spring-loaded sensor tip which ensures accurate contact, and the metal detector protects against false readings caused by the presence of e.g. "handles" or other metal elements. (detection of metal causes a continuous signal, while a diamond is intermittent). The device has a box and an aesthetic case , making it a perfect gift. Specification: High quality High accuracy Easy-to-read LCD and LED display Acoustic and visual measurement result Powered by DC 9V battery x 1 (not included)