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 19 ARTIFICIAL RESPIRATION OR OTHER THERAPEUTIC RESPIRATION APPARATUS. 90 19 20 OZONE/OXYGEN/AEROSOL THERAPY,ART.RESPIRATION OR OTH.THERAPEUTIC RESP. APP Commodity Code Description 90 19 20 00 OZONE/OXYGEN/AEROSOL THERAPY,ART.RESPIRATION OR OTH.THERAPEUTIC RESP. APP