Section 18 OPTICAL, PHOTOGRAPHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION , MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; M USICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 90 Optical, photographic, cinematographic measuring, checking, precision, medical o 90 14 Direction finding compasses; other navigational instruments and appliances. 90 14 20 Instruments and appliances for aeronautical or space navigation (other than compass Commodity Code Description 90 14 20 00 Instruments and appliances for aeronautical or space navigation (other than compass