Section 18 OPTICAL, PHOTOGRAPHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION , MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; M USICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 91 Clocks and watches and parts thereof 91 10 Complete watch or clock movements, unassembled or partly assembled (movement set Commodity Code Description 91 10 11 91 10 12 91 10 19 91 10 90