Harpenden Caliper Calibration Block
The Caliper 10mm Calibrator Block for testing ensures that your body fat tongs are calibrated and your readings are accurate.
The reading screen has 2 needles, one large, one small. Each full rotation of the large needle represents 2 cm (20mm), indicated by the small needle. For example, if you do one full rotation and then it reaches 5, it would be 25mm.