37 CUSTOM MANUFACTURE, CONSTRUCTION, INSTALLATION, MAINTENANCE AND REPAIR SERVICES OF MACHINES FOR MANUFACTURING AND TESTING FILTERS FOR USE IN THE AERONAUTICAL INDUSTRY AND ENGINES AND OF MECHANICAL PARTS OF SAID MACHINES; CUSTOM MANUFACTURE, CONSTRUCTION, INSTALLATION, MAINTENANCE AND REPAIR SERVICES OF MACHINES AND THEIR MECHANICAL PARTS FOR MANUFACTURING AND TESTING MOTORS AND ENGINES AND FILTERS; NAMELY, HYDRAULIC MOTOR FILTERS, AIR FILTERS AND FILTERS FOR AIR CONDITIONING UNITS; CUSTOM MANUFACTURE, CONSTRUCTION, INSTALLATION, MAINTENANCE AND REPAIR SERVICES FOR FILTERS