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 02 Lenses, prisms, mirrors and other optical elements, mounted, nes 90 02 20 Filters Commodity Code Description 90 02 20 00 Filters