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 02 Lenses, prisms, mirrors and other optical elements, of any material, mounted, be Commodity Code Description 90 02 11 90 02 19 90 02 20 90 02 90