Subheading 901710: Drafting Tables and Machines; whether or not Automatic

Subheading 901720: Drawing, Marking-out or Mathematical Calculating Instruments

Subheading 901730: Mathematical Equipment; Micrometers, Callipers and Gauges

Subheading 901780: Mathematical Instruments and Equipment; N.E.C. in Heading No. … etc.

Subheading 901790: Drawing, Marking-out Equipment and Mathematical Instruments; … etc.