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, me Thereof. 90 15 Surveying (including photogrammetrical surveying), hydrographic, oceanographic, hydrological, meteorological or geophysical instruments and appliances, excluding compasses; rangefinders 90 15 20 - Theodolites and tachymeters (tacheometers) Commodity Code Description 90 15 20 00 - Theodolites and tachymeters (tacheometers)