Rolex · Sea-Dweller

Strap for Rolex Sea-Dweller 1665 (Double Red / Great White)

Takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width20 mm
Case diameter40 mm
Reference1665
FamilySea-Dweller
Year1967-1980
CaseStainless Steel
CrystalAcrylic
Water resistance200

Recommended spring bar

Spring bars Rolex vintage 20mm × 2mm — drilled lugs

Verified compatibility for this reference · lug 20 mm · Ø 2 mm · drilled lugs

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Straps for the Sea-Dweller 1665

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The Sea-Dweller 1665, seen from the bench

The Rolex Sea-Dweller 1665 (Double Red / Great White), produced from 1967 to 1980, is a radical diving instrument developed in collaboration with COMEX for professional saturation diving operations at depths exceeding 300 metres. The stainless steel 904L Oyster case measures 40mm in diameter and features a helical valve on the case side for controlled helium decompression during ascent from hyperbaric chambers. The automatic calibre 1570 (later 1575) movement is water-resistant to 610 metres, with a unidirectional aluminium bezel and 60-minute graduations. Lug-to-lug: 20mm.

Frequently asked questions

What is the lug width of the Rolex Sea-Dweller 1665?

The Rolex Sea-Dweller 1665 features 20mm lugs. This lug width remained consistent throughout the reference's entire production run, from 1967 to 1980. When replacing the strap, a 20mm attachment width at the lugs is required, ideally tapering to 16mm at the buckle end.

What is the best aftermarket strap for the Rolex Sea-Dweller 1665?

For the Sea-Dweller 1665, the most suitable materials are smooth-grain calf leather or alligator leather in black or dark brown, which complement the technical character of the case without overwhelming it. Alternatively, a ballistic nylon NATO strap or a vulcanised rubber strap pays homage to the reference's original diving vocation. The choice ultimately depends on intended use: daily wear or occasional.

How do you change the strap on a Rolex Sea-Dweller 1665?

To replace the strap on the Sea-Dweller 1665, the spring bars connecting the strap to the case lugs must be removed using a dedicated spring bar tool or a fork-tip lever tool. Insert the new spring bar into the first strap lug end, compress it, and engage it into the case lug. Care should be taken to avoid scratching the polished steel lugs during the operation.

Are there compatible aftermarket straps for the Rolex Sea-Dweller 1665?

Yes. Any strap with a 20mm attachment width is technically compatible with the Sea-Dweller 1665. Milano Straps offers a curated selection of handcrafted 20mm straps specifically compatible with this reference, available in various materials and finishes. It is advisable to also verify the end tip shape (straight or curved) to ensure the best fit against the Oyster case lugs.

How long does a leather strap last on a Rolex Sea-Dweller 1665?

The lifespan of a leather strap depends on leather quality, tanning method, and daily use. A vegetable-tanned calf leather strap of artisanal quality, kept away from water and humidity, typically lasts 2 to 4 years with regular use. High-grade alligator straps, owing to their denser and more resilient leather, can last 5 to 7 years. Milano Straps products carry an 18-month warranty against manufacturing defects.

The next step

The right strap isn't chosen. It is built, together.

From the atelier appointment to delivery, every step is made for those who know that things done well take time. Rare leathers, one piece at a time, eighteen months of warranty.

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Casati Milano · Via XX Settembre 15, Milan · by appointment only