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 12 Microscopes, other than optical microscopes; diffraction apparatus 90 12 90 Parts and accessories of microscopes other than optical microscopes; diffraction apparat Commodity Code Description 90 12 90 00 Parts and accessories of microscopes other than optical microscopes; diffraction apparat