These Centaflex couplings and joint shafts have been specially designed for applications in boats and yachts, for the connection of reversing gears and propellor shafts.Torsionally elastic, backlash free, potentially damaging torsional vibration produced by the engine is dampened, especially at low speeds. Additionally, noise is dampened by up to 5 dBA, the rubber of the coupling does not lead the noise of the engine to the hull. Reduced vibrations protect allm parts of the unit in particular those of electronics. The couplings compensate for all types of misalignments, particularly angular, thus reducing wear on the shaft bearing and gearbox.