Omega · Speedmaster Moonwatch

Strap for Speedmaster Professional Moonwatch 3861 Stainless Steel / Black / Plexi / Kanjar Oman

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

Lug width

20mm

20 mm straps All Omega

Lug width20 mm

Case diameter42 mm

Reference310.30.42.50.01.003

FamilySpeedmaster Moonwatch

MovementOmega caliber 3861 small seconds, hours, minutes | Chronograph | chronometer

Year2023

CaseStainless Steel

Recommended spring bar

Spring bars Omega 20mm — 1.8mm diameter

Technical match for lug width and diameter · lug 20 mm · Ø 1.8 mm

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Straps for the Speedmaster Moonwatch 310.30.42.50.01.003

Selected for the 20 mm lug width · workshop selection

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The Speedmaster Moonwatch 310.30.42.50.01.003, seen from the bench

The Speedmaster Professional 310.30.42.50.01.003 is the only NASA-certified chronograph for extravehicular operations, representing the direct evolution of the 1969 lunar model worn by Buzz Aldrin. Its 42.00 mm stainless steel brushed case houses the Omega caliber 3861 movement, featuring a column wheel chronograph mechanism, 21,600 hourly beats, and 48-month power reserve. The 20 mm lug width accommodates standard straps without forcing, ensuring secure and rapid strap changes while maintaining visual balance with the black anti-reflective dial and original tachymeter scale.

Frequently asked questions

What is the lug width of the Omega Speedmaster Moonwatch 310.30.42.50.01.003?

The strap width of the Speedmaster Professional 310.30.42.50.01.003 is 20 millimetres. This dimension is precise and certified: measure the straight-line distance between the spring bar attachment points inside the case to verify the compatibility of a strap.

What is the best strap material for this Omega model?

Alligator remains the optimal choice for formal elegance, while vegetable-tanned shell cordovan develops a deep patina over time that honours the brushed steel case. For daily wear, a thick canvas NATO or structured rubber offer mechanical resistance and tactile comfort.

How do I change the strap on my Speedmaster 310.30.42.50.01.003?

Use a spring bar tool (Y-shaped or lever type) to remove the spring bars inside the lugs. Insert the lever into the small lateral holes of the spring bar, gently lift to free the pin from the case seat, remove the old strap and fit the new one. The procedure takes just a few minutes and requires no specialized tools.

Can I use an aftermarket 20mm strap on this model?

Yes, any strap with a 20mm lug width is compatible. Verify that the strap ends have a 20mm width for at least 2-3 centimetres from the termination to ensure correct housing in the case lug pins.

How long does a leather strap last on a chronograph like the Speedmaster?

An alligator or vegetable-tanned calf strap lasts on average 3-5 years in daily wear, depending on frequency of changes and exposure to sweat, moisture and UV rays. Shell cordovan, thanks to fibre density, can exceed 7-8 years. Tropic rubber straps last 4-6 years before irreversible rubber hardening.

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