The Rolex Sea-Dweller Deepsea reference 136660 was introduced in 2022, marking the latest evolution (MK I generation of this reference) of Rolex's ultra-deep saturation diving watch.

  The reference 136660 replaced the previous 126660 generation. While it looks nearly identical at first glance, Rolex introduced minor refinements to improve visual aesthetics and daily functionality: 

• Case & Dimensions: A robust 44mm stainless steel Oystersteel case with a thickness of 17.5mm. 

• The Bezel & Crystal: The black ceramic Cerachrom bezel was slightly slimmed down. The 5.5mm thick sapphire crystal features a chamfered (beveled) edge for a cleaner visual profile. 

• Larger Date Window: The date window and underlying date disc were increased in size by roughly 8%, providing better legibility.

• Bracelet and Clasp: Features optimized bracelet proportions. Crucially, Rolex removed the Fliplock extension link from the Oysterlock safety clasp on this reference, retaining only the Glidelock micro-adjustment system to make the clasp sit flatter on the wrist. 

• Case Back: Engineered with an updated titanium case back clearly engraved with "Titanium RLX".

• Water Resistance: Retains the engineering feat of 3,900 meters (12,800 feet) of water resistance utilizing the patented Ringlock System and a helium escape valve. 

• Movement: Powered by the high-precision, automatic Rolex Calibre 3235, providing a robust 70-hour power reserve.