The Rhino Coffee Gear Thermometer Calibration tool features a box end wrench to suit the Rhino Coffee Gear Tall and Short Analogue Thermometers.
Specifications:

Dimensions: 88mm (L) x 4mm (D) x 21mm (W)
Wrench Size: 10 / 11mm (dual sizes allow both new and old versions of the Rhino thermometer to be calibrated)
Material: Perspex (Clear)

How to Calibrate:

Locate the nut at the top of the thermometer stem
Using the Calibration Tool, simply adjust the needle position so that it shows the correct temperature
While holding onto the dial/face, lock the spanner onto the recalibration nut at the rear of the dial
To increase the temperature, turn the recalibration nut in a clockwise direction
To decrease the temperature, turn the recalibration nut in a counter-clockwise direction