From Watches Wiki
with the typical Oyster case and Oyster bracelet
Watch type (name is used only by Rolex)
Oyster is the designation for the best known sports and luxury watches series by Rolex. The first Rolex "Oyster" was presented in 1926, as the world's first patented waterproof watch.
Cases of this series are milled out of solid stainless steel. All models have a screwed-down caseback and a screw-in crown.
Rolex uses the term "Oyster" also for its three-row bracelet ("Oyster bracelet"). The special models such as the Rolex Submariner, Rolex GMT-Master II or Rolex Explorer are equipped with this type of wristband.