Omega · X-33 / Z-33
Strap for Omega X-33 / Z-33 3991.50.09
The Speedmaster X-33 Titanium / Green Kevlar / 2nd Gen takes 20 mm straps. Verified lug width, the straps that fit this model, and answers to the most common questions.
Lug width
Recommended spring bar
Straps for the X-33 / Z-33 3991.50.09
Selected for the 20 mm lug width · workshop selection
Black Alligator Strap with Light Blue Edges€149
Red Alligator Strap Water Resistant€195
Green Rubberized Alligator Strap with Ecru Tribal Stitching€149
Hammered Calfskin Strap Light Blue€98
Vintage Olive Green Calf Leather Watch Strap★ 4.5 · 4€80
What I'm asked about the Omega X-33 / Z-33 3991.50.09
What strap size does the Omega X-33 / Z-33 3991.50.09 take?
The Omega X-33 / Z-33 3991.50.09 needs 20 mm between the lugs, usually 16 mm at the buckle. It's the size I've been fitting on it for years.
Can the strap on the Omega X-33 / Z-33 3991.50.09 be changed?
Yes. It has spring bars between the lugs: with the right tool the strap comes off in a minute. If you'd rather not risk a scratch, I do it in the workshop.
Can I put a leather strap on the Omega X-33 / Z-33 3991.50.09?
Yes, in 20 mm leather. On a 42 mm chronograph I like box calf: it holds its shape and carries a substantial case.
Which strap do you recommend for the Omega X-33 / Z-33 3991.50.09?
A 20 mm box calf. You'll find it ready in the 20 mm collection. If you'd rather have something built on your wrist, the Casati atelier.
The X-33 / Z-33 3991.50.09, seen from the bench
Frequently asked questions
What type of strap pairs best with the Omega X-33 / Z-33 3991.50.09?
A black alligator strap with vegetable tanning represents the ideal compromise: the natural grain texture dialogues with the brushed finish of titanium, maintaining the instrumental quality of the watch. Alternatively, a Cordura NATO strap with titanium-coated keeper offers maximum functionality without aesthetic compromise. We advise against glossy synthetic rubber, which betrays the technical identity of the timepiece.
Are aftermarket straps compatible with the Omega X-33 / Z-33 3991.50.09?
Yes, any strap with a 20mm lug width is compatible. Available in alligator , calf, shell cordovan , vegetable-tanned leather , and NATO straps. The important thing is to verify that the lug width is exactly 20mm and that the strap is sufficiently rigid for the case dimensions.
How long does a leather strap last on the Omega X-33 / Z-33 3991.50.09?
A quality leather strap (alligator, calf, cordovan) typically lasts 3-5 years under normal use conditions, considering that titanium is an inert material and does not degrade the fibers. With vegetable tanning , the leather develops a natural patina that improves with aging. Humidity and chlorine shorten durability; regular maintenance with natural wax extends it. NATO straps last longer (10+ years) because they are made of Cordura nylon.
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.
Request an appointment →Casati Milano · Via XX Settembre 15, Milan · by appointment only
The atelier's website: casatimilano.com