Authored by Tokunaga / Outremer2
Our research and development was done as the perfect He-mixed-gas diver's watch of the 6159 professional 600m diver's watch in 1975.
We designed the diver's watch as the development target that the inner pressure of the watch case did not go up in high-pressure helium mixture gas like Rolex etc., and the development of the special quality gasket of the material of Improved-IIR(Isobutylene-isoprene rubber) and in the structure development of the watch case we used the glass gasket of L type and one-piece case became the conclusive factor in the He-tightness.
As the result of the experiment, the penetration of helium gas is suppressed by about 1/100 to the conventional watch case, the inner pressure of the case does not turn into high pressure and the diver's watch of the ideal saturation diving specification which does not need "helium gas escape valve" is completed, and the SEIKO professional diver's watches lead the diver's watch world after that watch as "a diver's watch which is proud of the highest water- tightness and air-tightness in the world."
Please use forever regularly those SEIKO products which are proud of the excellent performance if you please.
Picture credit: Seiko