Calibration discs for Gemtest-PGI Magnifier Style_Reader (handheld) - can also be powered

- can also be powered with a USB cable (supplied)

it also gives a wider range of reading

Backlit display with lots of information

10X12 - 10X13 - 10X14 - 10X20* - 10X21 - 10X21 - 10X23 - "30X21”

Battery included

Calibration discs for Gemtest-PGI Magnifier Style_Reader (handheld) - can also be poweredDetails Spare calibration discs for GEMTEST PGI. The Gemtest PGI must be calibrated regularly to ensure it is working properly, especially if the temperature changes. This is not difficult: you place the probe on of the circles and press a button, then place it on the other circle and press a button. The only problem is: if you've lost the calibration discs.