Omega · Speedmaster (Non-Moonwatch)

Strap for Speedmaster Moonwatch Co-Axial White Side of the Moon Diamond

Takes 21 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.

Lug width21 mm
Case diameter44 mm
Reference311.98.44.51.55.001 (aka: 31198445155001)
FamilySpeedmaster (Non-Moonwatch)
MovementOmega caliber 9300 hours, minutes, small seconds | date | Chronograph, column wheel | chronometer, co-Axial escapement
Year2015
CaseCeramic

Recommended spring bar

Omega Spring Bars 21mm — Single Diameter

Technical match for lug width and diameter · lug 21 mm · Ø 1.8 mm

All Omega spring barsOpen →

Straps for the Speedmaster (Non-Moonwatch) 311.98.44.51.55.001 (aka: 31198445155001)

Selected for the 21 mm lug width · workshop selection

All 21 mm straps →

The Speedmaster (Non-Moonwatch) 311.98.44.51.55.001 (aka: 31198445155001), seen from the bench

The Speedmaster reference 311.98.44.51.55.001 features the Omega 9300 automatic caliber with column-wheel chronograph function and co-axial escapement. The movement offers hours, minutes, small seconds and date display, with chronometer certification. The lugs measure 21mm in width.

Frequently asked questions

What is the lug width of the Omega Speedmaster (Non-Moonwatch) 311.98.44.51.55.001?

The lug width is 21mm. This dimension is specific to the model and is essential when selecting an aftermarket strap. To verify it, measure the internal distance between the spring bars: 21mm precisely guarantees complete compatibility with any strap of that size.

What is the best strap for the Speedmaster (Non-Moonwatch) 311.98.44.51.55.001 in grey ceramic?

Vegetable-tanned alligator with coarse grain, preferably in aged cognac or pearl grey, creates the most refined aesthetic balance with the ceramic case. An excellent alternative is shell cordovan in burgundy tones. For pure sportiness, an anthracite grey NATO or black FKM rubber maintain the chronograph's austerity.

How do I change the strap on my Omega Speedmaster (Non-Moonwatch)?

Use a spring bar tool to gently remove the spring bars from the lugs. Insert the forked tip of the tool between the lug and the spring bar, applying light pressure to extract the bar from its seat. Repeat on the other side, then insert the new spring bars into the aftermarket strap, ensuring the lug width is 21mm.

Can I use a 21mm aftermarket strap with my 311.98.44.51.55.001?

Yes, completely compatible. Ensure that the strap is specifically sized at 21mm (lug width) and that the spring bar is calibrated for this width. Casati Milano straps and models available online at milanostraps.it for the 21mm size are tested for complete compatibility.

How long does a leather strap last on a watch like the Omega Speedmaster (Non-Moonwatch)?

A quality leather strap (alligator, cordovan, calf in vegetable tanning) lasts 3-5 years of daily use. Duration depends on frequency of use, exposure to sweat and humidity, and maintenance (periodic cleaning and conditioning). Casati Milano straps come with an 18-month warranty excluding natural wear.

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