Watches with a 24 mm lug width: the list and the traps
Founder & CEO, Smartlet - CentraleSupelec engineer - Concours Lepine 2025, Awarded - CES 2026
Contents
A 24 mm lug width is a statement before it is a measurement. It belongs to watches that want to be seen from across a room: dive watches built like hardware, pilot chronographs with a bezel you could steer with. Go through a compatibility database family by family and the pattern is quick to find, since 24 mm sits on the large case of a range while the smaller case stays at 22. The surprises come from elsewhere. Some of the best-known 24 mm watches hold their strap with screws, and some brands list widths that end in .05. Below is the list, built from the lug widths recorded in the Smartlet compatibility database, with the exceptions and the traps.
- The pattern. 24 mm follows large tool watches, from the Luminox Navy SEAL family to the 46 mm Breitling Navitimer B01.
- The exceptions. Square and rectangular cases reach 24 mm at smaller sizes, like the 39 mm Bell & Ross BR S.
- The screw trap. Many 24 mm Panerai Luminor references and some Bell & Ross cases hold the strap with screws, which rules out a Smartlet.
- Fractions. Breitling references listed at 24.05 mm are marked not compatible. Whole numbers only.
- The ceiling. 24 mm is the top of the 18 to 24 mm range the Smartlet covers. The 26 mm cases are out.
The pattern: 24 mm follows the large tool watch
If 18 mm follows the small case, 24 mm follows the big one. In the Smartlet compatibility database the width clusters on round cases of 44 mm and up, most of them built for diving or for the cockpit. When a brand draws the same design in two sizes, the bigger one tends to step up to 24 while the smaller stays at 22. Proportion again, at the other end of the scale.
| Watch | Case | Lug width (Smartlet database) |
|---|---|---|
| Luminox Navy SEAL 3500 and 3250 | 44 to 45 mm | 24 mm |
| Breitling Navitimer B01 Chronograph 46 | 46 mm | 24 mm (22 mm at 41 and 43 mm) |
| Breitling Superocean Automatic 46 | 46 mm | 24 mm (22 mm at 42 and 44 mm) |
| Hamilton Khaki Navy BeLOWZERO | 46 mm | 24 mm (22 mm at 42 mm) |
| Hanhart Primus Fly Navy | 44 mm | 24 mm |
| Oris Williams and TT1 | 42 to 45 mm | 24 mm |
| Glycine Combat Sub 48 | 48.5 mm | 24 mm |
| Omega Seamaster PloProf 1200M | 55 mm | 24 mm |
Lug widths as recorded in the Smartlet compatibility database, by model and case size. References inside one family can differ, so check yours on the brand pages, for example Breitling or Oris, before ordering anything for it.
Luminox is the cleanest case. Nearly every Navy SEAL reference we hold sits at 24 mm, from the 3500 to the Master Carbon, and the brand keeps the width on its smaller 42 mm field pieces too. A wide strap on a wide case is half the look. For the military habits this kind of watch comes from, read our piece on why special forces wear their watch inverted.
The exceptions: smaller cases at 24 mm
A few watches reach 24 mm without a big round case. The Bell & Ross BR S measures 39 mm, but it is square, and a square case carries lugs about as wide as its body. The Girard-Perregaux Vintage 1945 XXL does the same with a rectangle 36.1 mm across. Shape sets the width here, more than size.
Yema's Wristmaster Traveller, at 39 mm, sits in between: one reference in our database takes 24 mm spring bars, while others in the same line come on an integrated bracelet and are marked not compatible. CODE41 uses 24 mm lugs across its 41.5 and 42 mm cases, which puts a fairly ordinary size at the top of the width range.
A family name tells you less than you would like. The Breitling Navitimer B01 is 22 mm at 41 and 43 mm and 24 mm at 46 mm, and the Superocean takes the same step. Our Navitimer guide goes reference by reference.
The trap: 24 mm watches held by screws
This is where 24 mm gets awkward. Several of the most famous 24 mm watches hold their strap with a bar screwed through the lugs, or with a screw and a tube, instead of a spring bar. The width matches. The attachment, which nobody looks at when buying a strap and which sits hidden inside the lug until the day you try to change it, does not.
Panerai is the obvious one. Most Luminor 44 mm references sit at 24 mm, and in our database several are marked not compatible because the strap is fixed by screwed bars, while many others are still being checked. Same width, two verdicts. Our Panerai Luminor guide explains how to tell which one you have, and the Panerai compatibility page lists the references we hold.
Bell & Ross is the other. Our database records screws and tubes on the BR 01 case and on some BR-X1 references, so they are marked not compatible even though the width is right. The square BR S, on spring bars, is the one that works. The Bell & Ross page has the detail.
The reason is mechanical. A watch adapter seats in the lug hole, where the spring bar used to be, and a bar screwed through the lugs leaves no hole free. Our piece on the lug hole and the pin goes into the detail, and the spring bar anatomy piece shows what a standard bar looks like.
The other trap: widths that end in .05
Breitling lists some references at fractional widths, 22.05 or 24.05 mm. In our database, Breitling references with a non-integer lug width are marked not compatible, while their whole-number siblings can be compatible. Two Navitimer B01 Chronograph 46 references, both documented on Breitling's own site, land on opposite sides of that line. Five hundredths of a millimetre, and a different answer.
Above 24, the range simply ends. The 26 mm lug width of the large 47 mm Panerai cases sits outside the 18 to 24 mm the Smartlet covers. The Oris Aquis at 24 mm is out for a different reason, since our database records an integrated bracelet on those references.
A 24 mm watch on a Smartlet
At 24 mm a watch sits at the top of the Smartlet range. The original strap comes off and two watch adapters seat in the lug holes, in place of the spring bars. Their width is chosen at order, 24 mm here, and the Smartlet bracelet sides lock into them.
The mechanical watch stays on top of the wrist. The smartwatch goes underneath, in the central part of the bracelet, on its own adapters: the Apple Watch adapters in both sizes are in the box, with a pair of standard smartwatch adapters for 18 to 24 mm lugs. Large watches carry weight of their own, and the Smartlet weighs 85 to 95 g with the connected device; our strap weight comparison puts that figure in context.
The first installation of the watch adapters takes under 10 minutes with the spring bar tool included in the box, and the set-up page shows each step. On a 46 mm watch the lug-to-lug matters as much as the width, since it decides whether the case overhangs your wrist.
How to confirm 24 mm on your own watch
Lug width is measured inside the lugs, from the inner face of one lug to the inner face of the other, at the height of the spring bar. Calipers give the cleanest reading. Any pair will do. At this size the bigger risk lies elsewhere, in missing what actually holds the strap.
- Take the strap off and look at the lugs. A spring bar leaves a small hole on the inner face, while a screwed bar shows a screw head on the outside of the lug.
- Read the gap between the lugs at the hole, with calipers if you can.
- Look for a fraction: a brand that lists 24.05 mm means 24.05.
- Confirm your exact reference on the compatibility pages before ordering watch adapters.
If you read 23 mm, note that the Smartlet lists that width as coming soon. For narrower watches, the 18 mm list works the same way, and the complete lug width guide has the method in more detail.
Smartlet, the modular metal bracelet awarded at the Concours Lepine 2025 and shown at CES 2026, covers lug widths from 18 to 24 mm. Discover the Smartlet One.
