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 21 Orthopaedic appliances, including crutches, surgical belts and trusses; splints 90 21 10 90 21 10 00 Commodity Code Description 90 21 10 00 00 - Orthopaedic or fracture appliances 90 21 21 00 00 -- Artificial teeth 90 21 29 00 00 -- Other 90 21 31 00 00 -- Artificial joints 90 21 39 00 00 -- Other 90 21 40 00 00 - Hearing aids, excluding parts and accessories 90 21 50 00 00 - Pacemakers for stimulating heart muscles, excluding parts and accessories 90 21 90 00 00 - Other