The respiratory gas mixture in the overpressure perched chamber mostly are composed of helium, and watch with divers body reaction is very close. Watchcase internal is filled with helium, because the pressure is the same as the perched chamber. Because helium is very light and highly volatile, and its molecular volume is the world's smallest, so the helium will gradually infilter from rubber gasket into the wrist watch. In the relief phase, the speed of the helium releasing in human tissue is faster than the waterproof watch and results accumulated in the pressure inside the casing. Divers would be observed during decompression watch mirror as the internal pressure, and like a champagne to plug a pop up from the bottle. We can see that the watch is also required effectively release the redundant helium inside the watch case.

In fact, rolex replicas are not aimed at making the helium wrist watch, but to an almost impossible task, that is equipping a one-way valve on the side of the case. When the case beyond a specific level of internal pressure, the device will automatically operate, already let the gas release from the case, and shall not affect the wrist watch waterproof performance. The design was specially designed for the new professional diving watch of the rolex sea dweller replica, and was patented in 1967, the helium gas valve is especially important for Sea Dweller saturation divers rising on the surface of the water action. The Comex soon appointed the Sea Dweller watch as specified watch, and all the divers continued to break through the limit of human deep-sea diving. First in 1988, a record of 534 meters deep, again in 1992 in hyperbaric oxygen chamber created test depth of 701 meters, the relief phase more for 24 days, but has yet to break the record.