9 Scientific, measuring, signaling, monitoring, and emergency apparatus and instruments, namely, a mechanical device to prevent explosion of an electrical transformer by depressurizing tanks, evacuating and eliminating gases from the transformer and avoiding contact between oxygen and evacuated explosive gases; firefighting apparatus for injecting neutral gases, namely, nitrogen injectors; firefighting apparatus for cooling explosive gases by means of mixing and stirring, namely, neutral gas injectors; fire extinguishing systems; apparatus for detecting fire, pressure, temperature, and fluid flow, namely, sensors; apparatus for closing, via fluid flow, changes in pressure, namely, conservator shutters and valves; apparatus for evacuating dangerous gases, namely, shutters, valves, pipes, separation tanks and neutral gas injectors for explosive gas elimination; apparatus for smothering fires, namely nitrogen drain and stir fire extinguishing systems, separation tanks and depressurization tanks; electrical and electronic security and alarm apparatus and instruments against explosions, fires and for suppression, namely indicator lights, sirens, temperature and level warning indicators, emergency signal transmitters, and beacon lights; electrical and electronic apparatus, instruments and equipment for receiving, conducting, distributing, transforming, accumulating or controlling electrical energy, namely, transformers, circuit breakers inductors and cable boxes, junction boxes, control and command post enclosures; components for all of the above products, namely, on-load top changers, bushings and circuit-breakers; downloadable electronic publications in the nature of scientific articles in the field of electricity and the mechanical protection of transformers