The “jolly” fitting is a PATENT OF INVENTION DEPOSITED 93A000893. It has the prerogative to allow us to choose and assemble with a simple “click” the thread that we need. Once assembled, it has exactly the same use and characteristics of a normal swivel fitting (see page 67) with the difference of being able to offer a wider range of threads, thus drastically reducing the coupling problems that occur in installation phase and consequently the inconvenient and costly use of the reductions. In nickel-plated brass, the degree of protection certified according to CEI EN 61386 between the fitting and the pipe is IP67 and is guaranteed by the sealing ring that tightens on the pipe when the nut is tightened, thus ensuring a perfect mechanical seal, to traction to torsion and vibration. The electrical continuity is instead guaranteed by the internal ferrule that is screwed directly inside the metal core of the tube, completely covering the end of the flexible tube to protect the cable passage.