Section 18 Optical, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; clocks and watches; musical instruments; parts and accessories thereof 91 Clocks and watches and parts thereof 91 01 Wrist-watches, pocket-watches and other watches, including stop-watches, with case of precious metal or of metal clad with precious metal. 91 01 91 Electrically operated 91 01 91 00 Electrically operated Commodity Code Description 91 01 91 00 000 Electrically operated