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, photographic, cinematographic, measuring, checking, precision, medical or surgical instruments and apparatus; parts and accessories thereof 90 21 Orthopaedic appliances; splints, etc; artificial parts of the body, etc 90 21 40 Hearing aids, excluding parts and accessories Commodity Code Description 90 21 40 00 Hearing aids, excluding parts and accessories