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 31 Measuring or checking instruments, appliances and machines, not specified or included elsewhere in this Chapter; profile projectors. 90 31 80 Other instruments, appliances machines Commodity Code Description 90 31 80 00 Other instruments, appliances machines