Resting directly below "Oyster Perpetual" on the cream dial of this classic, 35 millimeter Rolex wristwatch is a depth-rating in small font, which reads " 50 m=165 ft." This detail may seem minor; however, it is quite significant. A depth-rating can be found on all Submariners and Sea Dwellers, but rarely are depth-ratings stamped on non-sports watches, such as this ref. 6567. I believe this watch is a piece unique Rolex.