Dietrich · OT

Strap for OT-4

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

Lug width20 mm
Case diameter46 mm
ReferenceOTCAO4
FamilyOT
MovementMiyota caliber 82S7 Additional 24 Hour Hand (fixed), Small Seconds, Hours, Minutes
CaseCarbon, Stainless Steel

Spring bar

Swiss Standard universal spring bars

The right category for this model · 316L steel, all lug widths 13–26 mm

Straps for the OT OTCAO4

Selected for the 20 mm lug width · workshop selection

All 20 mm straps →

The OT OTCAO4, seen from the bench

The Dietrich OT reference OTCAO4 is powered by the Miyota Calibre 82S7 movement with hours, minutes, small seconds and a fixed 24-hour hand. The timepiece features an unconventional design characterized by a particular arrangement of the dial elements. Technical specifications regarding case dimensions and materials are not available for this model.

Frequently asked questions

What is the lug width of the Dietrich OT OTCAO4?

The Dietrich OT OTCAO4 features a 20mm lug width, measured as the distance between the two pins connecting the strap to the case. This dimension is critical to verify before purchasing a replacement strap, particularly given the integrated asymmetrical architecture of this model's lugs, which demands precise engineering tolerances.

What is the best strap choice for the Dietrich OT OTCAO4?

The optimal strap choice depends entirely on your stylistic interpretation. A genuine alligator strap with vegetable tanning complements the contemplative nature of the case design, whilst a technical NATO strap emphasises its instrumental character. For maximum comfort and practicality, a high-quality technical rubber strap represents the most versatile solution. The key recommendation is selecting materials of sufficient quality to complement the geometric rigour of the carbon and stainless steel case.

How do you change the strap on a watch with integrated lugs?

Replacing a strap on a 20mm integrated lug requires a specialised tool to compress the bayonet spring mechanism. Secure the watch in a stable holder, locate the micro-protrusion of the spring beneath the lug, compress it gently, and slide the strap outward. Reverse the procedure for installing the new strap. If uncertain about the process, consult a professional watchmaker.

Which aftermarket straps are compatible with the OTCAO4?

Any strap with a 20mm lug width is compatible with the Dietrich OT OTCAO4. Browse our 20mm strap collection on milanostraps.it, featuring options in alligator leather, calf, shell cordovan, NATO, and rubber. Always verify that the strap width remains proportionate to the 46mm case diameter and that the bayonet spring mechanism suits your specific model.

How long does a leather strap last on a daily-wear watch?

Leather strap longevity depends on maintenance, frequency of wear, and specific material quality. A premium alligator or calf strap worn daily typically lasts 3-5 years before requiring replacement. Vegetable-tanned leather develops patina rather than deteriorating, extending both functional and aesthetic lifespan. Avoid prolonged exposure to humidity and direct heat, and occasionally apply a protective balm to slow natural ageing.

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