This 82xxxxx-serial Rolex Sea-Dweller “Spider Dial” Ref:16660 is rated 9 out of 10. It comes with green tag, anchor, booklet, box and paper dated in November 1987. The Rolex Sea-Dweller Ref. 16660 aka the “Triple Six” is an early and rare transitional piece. The perfect blend of vintage and modern Rolex design. Rolex implemented major changes to the Sea-Dweller starting in 1981. The sapphire crystal became standard starting with the Ref. 16660 and major developments were implemented into the model which included a uni-directional bezel as opposed to the bi-directional bezel found in previous examples, a larger and more reliable helium escape valve was added, and we see the introduction of the first solid end link (SEL) bracelets with the Ref. 93160 bracelets with attached 592 end links becoming standard around 1981-1982. The Sea-Dweller also received a new movement, the Cal. 3035 which allowed for Quick-Set date function. The ref. 16660 had an increased tested depth rating of 1220m as opposed to the previous 610m found in the Ref. 1665.