Duo gem tester (Presidium PDT-II) Options_For the partially sighted by touching it with your

by touching it with your finger) will give incorrect results

Four AAA batteries (supplied)

The Apex works fine on all 'brilliant' (round) cuts

diamond is singly refractive

this is particularly powerful) but also good for stamps and coins

Duo gem tester (Presidium PDT-II) Options_For the partially sighted by touching it with yourSummary Bench model. A dual tester with both thermal meter and reflectivity meter. Place the probe on the stone to operate analogue meter (the thermal meter, see detail in the extra pictures). Place the stone over the sensor (even if it's in jewellery) to operate the digital meter (the reflectivity meter). You don't have to use both systems, you can choose one or the other. Includes heavy duty nylon carrying case and a PP3 battery. Also a power supply