44 MEDICAL AND SURGICAL DEVICES-NAMELY, MUSCLE STIMULATORS; SONIC THERAPY UNITS; ELECTRODES AND FASTENING DEVICES THEREFOR; ELECTROCARDIOGRAPH AND CHART PAPER THEREFOR; OXYGEN BREATHING APPARATUS, NAMELY, OXYGEN REGULATORS, MASKS, LIQUID OXYGEN CONVERTERS AND CONTROLS THEREFOR; CLOSED LOOP OXYGEN SYSTEMS AND OXYGEN CONCENTRATION SYSTEMS; AND SURVIVAL KITS