9 ELECTRIC STORAGE BATTERIES FOR AUTOMOTIVE, DIESEL AND EMERGENCY LIGHTING, AND BATTERY GRIDS AND PLATES; SOLENOID-OPERATED SELECTOR VALVES FOR AIRCRAFT; PLUG, DUAL-ELEMENT, RENEWABLE AND ONE-TIME FUSES FOR COMMERCIAL AND INDUSTRIAL APPLICATIONS; TRAVELING WAVE TUBE AMPLIFIERS, MICROWAVE ACOUSTIC SOLID STATE DELAY DEVICES; WELDING ELECTRODES; FILMS FOR ENGINEERING REPRODUCTION AND MICROFILM DUPLICATING; REGULATOR VALVES, CHECK VALVES, FLOW AND LEVEL INDICATORS; NOSEWHEEL STEER AND DAMPER UNITS INSTALLED TO AID IN MANEUVERING THE NOSEWHEEL OF AIRCRAFT; AND AIR AND WATER ENVIRONMENTAL CONTROL SYSTEMS-NAMELY, OXYGEN ANALYZERS, COMBUSTIBLE ANALYZERS, FLUE GAS ANALYZERS, PHOTOMETRIC ANALYZERS, THERMAL CONDUCTIVITY AND HYDROCARBON ANALYZERS, AND MEDICAL OXYGEN ANALYZERS