sentences:  Rolex Sea Dweller
  
  The Rolex Oyster Perpetual Date Sea-Dweller is a line of diver's watches manufactured by Rolex, with an underwater diving depth rating of 1,220 meters (4 000 ft) and up to 3,900 metres (12,800 ft) for the Sea-Dweller Deepsea model.Launched in 1967 with a diving depth of 610 metres (2 000 ft), the Sea-Dweller features a gas escape valve, developed by the brand specifically for watches, which allows the helium trapped in the watch while decompessing to be released at a given pressure during decompression, while preserving the watch case's water resistance.