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 14 OTHER CLOCK OR WATCH PARTS. 91 14 10 SPRINGS, INCLUDING HAIR-SPRINGS Commodity Code Description 91 14 10 00 SPRINGS, INCLUDING HAIR-SPRINGS