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, PHOTOGRAGHIC, CINEMATOGRAPHIC, MEASURING, CHECKING, PRECISION, MEDICAL OR SURGICAL INSTRUMENTS AND APPARATUS; CLOCKS AND WATCHES; MUSICAL INSTRUMENTS; PARTS AND ACCESSORIES THEREOF 90 21 HEARING AIDS AND OTHER APPLIANCES WHICH ARE WORN OR CARRIED OR IMPLANTED 90 21 40 HEARING AIDS, EXCLUDING PARTS AND ACCESSORIES Commodity Code Description 90 21 40 00 HEARING AIDS, EXCLUDING PARTS AND ACCESSORIES