Made of polyoxymethylene (POM).
The test rod length of 100 mm
Diameter of (12.50 ± 0.01) mm and a contact area of 123 mm2.
The total weight of the test rod and the indicator ring shall be 10.0 (-0, +0.2) g.
The indicator ring height of 20 mm and an inner diameter about 12 mm.
The adjustment clamp height of 10 mm. 
The base plate made of polycarbonate (PC).
The base plate diameter between 70 mm and 100 mm.