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 14 Direction finding compasses; other navigational instruments and appliances 90 14 20 Instruments and appliances for aeronautical or space navigation(other than compasses) Commodity Code Description 90 14 20 00 Instruments and appliances for aeronautical or space navigation(other than compasses)