Rolex Sea Dweller 40mm Oystersteel Black Dial Black Aluminum Unidirectional Bezel Oyster Bracelet 16600 a day of the month

a day of the month sub-dial

enabling drivers to measure speeds up to 400 units per hour

and sapphire crystal protection

secured by the Oysterclasp with Easylink extension

Rolex Sea Dweller 40mm Oystersteel Black Dial Black Aluminum Unidirectional Bezel Oyster Bracelet 16600 a day of the monthOne of the last true tool watch Sea Dwellers before Rolex shifted the line toward larger, more modern proportions, the 16600 has built a strong following among collectors who prefer the classic proportions and no nonsense design. The clean black dial paired with the aluminum bezel insert keeps it firmly rooted in its professional diving origins. Its a reference that continues to gain traction, especially with earlier 2000s examples as supply tightens.