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 81 Hydraulic or pneumatic Commodity Code Description 90 32 81 00 Hydraulic or pneumatic
