Binocular Headband Magnifier, professional Magnifier Style_Head-worn We have a 620g model

We have a 620g model which is far less

brightness

A refractometer measures refraction (bending) of light as it passes through the gemstone (like poking a stick into clear water)

Combine 15X with 10X to give 25X

You will need a sample of 18ct yellow gold to 'match' the electronics in the tester to the reading on the display (technical term: calibration)

Binocular Headband Magnifier, professional Magnifier Style_Head-worn We have a 620g modelSummary This is the type used by surgeons, instead of 'simple' lenses, they have a pair or very high quality tiny telescopes. This enables a unique combination of high magnification with a long working distance (choose the one that is best for you). Detail The optical quality of these is so good that you do not need high magnification, see our guide. As regards the working distance, sit at your workplace, sit comfortably upright, see how far it is