Section 18 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; clocks and watches; musical instruments; parts and accessories thereof 90 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof 90 17 Drawing, marking-out or mathematical calculating instruments (for example, drafting machines, pantographs, protractors, drawing sets, slide rules, disc calculators); instruments for measuring length, for use in the hand (for example, measuring rods and ta Commodity Code Description 90 17 10 Drafting tables and machines, whether or not automatic 90 17 20 Other drawing, marking-out or mathematical calculating instruments 90 17 30 Micrometers, callipers and gauges 90 17 80 Other instruments 90 17 90 Parts and accessories