26 [ PORTABLE AIR TRAFFIC CONTROL TOWERS ] BASE STILL PHOTOGRAPHIC LABORATORIES, ELECTRONIC SPEED INDICATORS AND SENSORS, ELECTRONIC STABILITY AUGMENTATION SYSTEMS FOR AIRCRAFT, PRESSURE TRANSDUCERS, TEMPERATURE CONTROLS, CABIN PRESSURE CONTROL SYSTEMS, GROUND SUPPORT EQUIPMENT FOR AIRCRAFT, SURFACE CRAFT, SUBSURFACE CRAFT AND SPACE CRAFT INCLUDING MAINTENANCE ND TEST EQUIPMENT, ELECTRONIC AUTOMATIC STABILIZATION EQUIPMENT FOR AIRCRAFT, SPACECRAFT AND WATERCRAFT, ELECTRONIC OR ELECTRICAL NAVIGATION SYSTEMS FOR USE IN AIRCRAFT, SPACECRAFT AND WATERCRAFT, GAS MANAGMENT ASSEMBLIES FOR SPACE TRAVEL, OXYGEN SUPPLY SYSTEMS FOR SPACE TRAVEL, PORTABLE LIFE SUPPORT SYSTEMS FOR SPACE TRAVEL, DIGITAL DRIVEN HARD COPY PLOTTERS, AND SPACE SUITS