It is an improved design.
It comes in two varieties:
C. Made of steelThis precision calliper enables measuring of internal and external dimensions and depth.
It is provided with a thumb wheel for easy motion of jaws, and comes in a velvet lined box or in a plastic case.
Measuring range: 15cm (or 150mm) /6 inch
Graduation: 1/10 mm / 1/128 inch.