Presidium standard+duo probe, old (before oct 2020) models Polishing compounds - cleaning and plating fluids For measuring specific gravity

For measuring specific gravity

Hold the light button to adjust brightness

see calibrating weighing machines

The same lens is available with a clamp to fix to the edge of ta workbench (if you prefer this

Presidium standard+duo probe, old (before oct 2020) models Polishing compounds - cleaning and plating fluids For measuring specific gravityDetails This probe has the old style connector, please check carefully to see if you have an old model or a new model, or it won't fit. It fits the following Presidium electronic gem testers: our ref. Gemtest P Presidium's ref. PGT and also the OLDER versions of our ref. gemtest duo Presidium's ref. PDT S7 Not sure which you have? See our information sheet.