نظرات ياداشت نغمه زنان - ادبيات و فرهنگ

+ 123

Some scuba diving replica watches intended for saturation diving at great depths are fitted with a helium or mixed breathing gas release or escape valve to prevent the crystal from being blown off by a pressure build up caused by helium that has seeped into the watch in helium enriched environments as the watch and diver adjust to normal atmospheric conditions.