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 32 Automatic regulating or controlling instruments and apparatus 90 32 90 Parts and accessories of automatic regulating or controlling instruments and apparatus Commodity Code Description 90 32 90 00 Parts and accessories of automatic regulating or controlling instruments and apparatus