The Delugs Micro-Adjust CTS Deployant Clasp Is A Small Upgrade That Makes A Big Difference
I reviewed some Delugs straps back in 2024, and since then, I’ve added a decent selection of the brand’s rubber CTS straps and sailcloth straps to my rotation. In fact, I recently bought a couple of sailcloth straps for some of the newer watches in my collection. So when Delugs kindly offered to send over the new Micro-Adjust CTS Deployant Clasp alongside a custom strap I had ordered, I was quite keen to see whether it would solve some of the few remaining little frustrations I had with the CTS system.
The basic idea is simple enough. This is the next evolution of the Delugs CTS deployant clasp, now with built-in micro-adjustment. If you’ve worn a rubber strap through a full day, especially in warm weather, you’ll know why that’s useful: your wrist changes size. Sometimes your strap feels perfect in the morning, then a bit snug by mid-afternoon. Other times, it’s the opposite. The Delugs CTS straps already give you a very clean cut-to-size fit, but once you’ve cut the strap, that’s pretty much it. There’s no going back. The previous CTS clasp did offer a little bit of adjustment between two notches, but you needed a tool to do it. That’s fine at home. It’s less useful when you’re out, your wrist has swollen slightly, and you just want the thing to feel right again.
A better clasp before we even get to the adjustment
Before getting into the actual micro-adjustment system, I want to talk about the clasp itself. I’ve seen and used a few previous versions of Delugs clasps, and one small thing that occasionally irked me was the way the two sides lined up when closed. Sometimes, it was just a fraction off. While nothing dramatic or anything that stopped me from wearing the strap, it was just enough to notice.
This new clasp feels like an upgrade in that regard. It’s still probably not 100% perfect, but given the spring-loaded butterfly format and the way both sides meet rather than overlap, I’m not sure absolute perfection is realistic here. This one feels about 98 or 99% there, which is a big step up. It looks tidier, it feels more composed, and it gives the whole strap a slightly more finished impression.
The other improvement I noticed straight away is comfort. The slight curvature was already introduced on the previous version, but the new curved edges also help a lot. I’ve had earlier clasps with sharper points that could occasionally dig into the underside of my wrist. This one feels smoother and less fussy in daily wear. That alone makes it better before we even get to the main feature.
Here, the strap is set to zero extension on either side.
The Fitwell system makes sense here
The new clasp uses the micro-adjustment feature developed with Fitwell Buckle Co. I already have one of Fitwell’s buckles in my rotation as well, but this is the first time I’ve seen the system integrated into a deployant clasp. It also marks the first time Delugs has been able to include toolless micro-adjustment on one of its CTS clasps, which makes sense given how compact and symmetrical the butterfly format needs to be.
The system gives you a 3mm extension on each side of the clasp. While it doesn’t sound like a huge amount on paper, on the wrist, a 6mm adjustment can be genuinely useful. It’s the difference between “this kinda fits” and “this fits properly.” Better still, it’s entirely tool-free. You don’t even need to take the watch off, let alone fiddle with a spring-bar tool, or commit to a new cut. You just give the strap a firm push or pull, and the clasp moves into the next position.
The left side has the extension engaged, while the right side does not.
There is a certain amount of resistance, and I think that’s important. You don’t want this thing shifting around accidentally while you’re wearing it. Delugs says the mechanism went through function testing and 1,000 pull-push tests, and the final version uses custom spring bars as part of the snap-fit system. That sounds like the sort of nerdy detail I enjoy, but what matters more is that it feels properly locked once adjusted.
On the Speedmaster Calibre 321
For this review, I fitted the clasp to a black waffle CTS strap and put it on my fairly new-to-me Omega Speedmaster Calibre 321. Now, the bracelet will always be number one for that watch. I’m not pretending otherwise. But I do like changing straps, and I’ve always enjoyed rubber on a Speedmaster when it’s done well. It changes the watch’s feel without making it look like it’s trying too hard.
On the black waffle CTS strap, the new clasp works really nicely. The Speedmaster Calibre 321 is a watch with a lot of charm and a very specific vintage-inspired feel, so I don’t want anything too glossy or bulky on it. This setup keeps things clean. The clasp sits neatly under the wrist, the strap has enough texture to keep it from feeling plain, and the whole thing gives the watch a slightly more relaxed wearing style.
If we’re talking about the 321, I have to include a photo of that beautiful movement…
In actual use, I’ll be honest, I haven’t had to use the micro-adjust feature much yet. The strap fit has been pretty spot on from the start. But I have used the Fitwell system before, and it’s one of those features that only really proves its worth when you need it. After a walk, on a hot day, after a flight, or when your wrist just randomly decides to be a different size for no good reason, being able to make a tiny adjustment without tools is a proper benefit.
Better here than on a buckle
One thing I hadn’t expected was that I actually prefer the Fitwell system in this deployant clasp. On the Fitwell buckle, the system works well, but when the tang moves forward, it doesn’t always sit quite as neatly in the groove of the buckle. It’s not a deal-breaker, but visually, you can tell something has moved.
With the Delugs deployant clasp, you don’t get that same little visual compromise. The adjustment remains hidden within the clasp system, so the whole thing stays tidier. It feels like a more elegant use of the idea. The mechanism is still easy to understand, but it disappears into the design rather than becoming part of what you see. That’s probably why I like this clasp more than I expected. It doesn’t feel like Delugs has bolted on a feature just for the sake of it. The adjustment actually suits the format. It adds something practical without making the clasp feel bigger, busier, or more complicated.
Price, sizing, and final thoughts
The Delugs Micro-Adjust CTS Deployant Clasp is made of 316L stainless steel and is available in 16mm, 18mm, and 20mm sizes. It comes in silver, yellow gold, rose gold, and black finishes, and it’s compatible with all Delugs CTS Rubber Straps. The clasp includes custom spring bars installed, plus two spares. At the time of writing, it’s listed on the Delugs website at the introductory price of €57.33 / US$70 / £49, reduced from €70.56 / US$80 / £56, and is available directly from the Delugs online store. One important note is to choose the clasp size based on the tapered end of the strap, not the lug width. For example, if you’re using a 20mm strap with a 4mm taper, you need the 16mm clasp. That might sound obvious if you’ve used a lot of deployant clasps, but it’s an easy mistake to make.
Overall, I think this is a proper upgrade. The micro-adjustment is the headline feature, but the better alignment, smoother edges, and improved comfort all play their part too. It’s a small component, but when a clasp is wrong, you notice it every time you wear the watch. This one gets a lot right, and if you already use Delugs CTS rubber straps, it’s most definitely worth the upgrade.
