ARCELI Diamond Tester Pen-High Accuracy Jewelry Diamond Tester＋60X Mini LED Magnifying, Professional Diamond Detector for Novice and Expert, Thermal Conductivity Meter It's rated 4.1/5 Star product on Amazon,With Great reviews. Amazon original Price: £14.99 + 4.99 postage it's like new just open box. you will need 12v battery to use it we tested it works. any questions dm us.
eBay