Developed as a deep sea expedition tool, Sea Dweller has an overwhelming waterproof performance of 4,000 feet (1,220 m) and 12,800 feet (3,900 m) of deep sea. Both models are equipped with a helium gas escape valve that automatically discharges helium gas during saturation diving. In addition, the Deep Sea is equipped with innovative technologies such as a dome-shaped sapphire crystal with a thickness of 5 mm and a proprietary ring lock system that increases the airtightness of the case itself as the water depth becomes deeper. It is designed to withstand water pressure and to operate normally at a depth of more than 100 times the depth where human beings can physically exist. It is a model that is truly worthy of the name Sea Dweller (ocean dweller).