This is a great tool to more conveniently measure your SG or Brix % when using your Grainfather. When using a hydrometer, you need to get a trial jar sample of wort from your Grainfather when it is near boiling and then wait for the wort to cool before getting a reading. With the refractometer you only need to take a small sample using a spoon or pipette straight from the Grainfather and only wait a few seconds before dropping a very small sample on to your refractometer.
Refractometer (0 to 32% Brix scale. Wort SG: 1.000 ~ 1.120)