I’ve said this before, and I’ll say it again: Jaeger-LeCoultre is a real “watch lovers’ brand.” Here is a super thin mechanical watch that also happens to have diamond decoration and a lot of hand-engraving on the skeletonized movement… surrounded by a ring of grand feu enamel painting. That is just layers of appeal all in one timepiece that could have easily just been “really thin.” Earlier in 2015, aBlogtoWatch debuted the Jaeger-LeCoultre Master Ultra Thin Squelette here, and now we’ve had some hands-on time with this rather incredible piece of mechanical artwork.

Allow me to clarify the title of this article by saying that while the Jaeger-LeCoultre Master Ultra Thin Squelette is the thinnest mechanical watch in the world (right now), the versions set with diamonds (as the ones we photographed are) add about a millimeter more thickness. Honestly, you’d probably never known unless someone pointed that out to you, but it is important to mention. Diamond setting requires that a canal be carved into the case material for the diamonds to sit in – and that takes the incredibly thin 3.6mm thick case of the non-diamond-set Jaeger-LeCoultre Master Ultra Thin Squelette to 4.73mm thick with these diamond-decorated models.

Still, put this “fatter” diamond-set version of the Jaeger-LeCoultre Master Ultra Thin Squelette watch on your wrist, and you still feel as though you are wearing a wafer. The case, in 18k white or pink gold, hardly appears thicker than the attractive rolled alligator strap. For the record, these types of straps on dress watches are my favorite. Visible stitching is just terribly overrated, in my opinion… At 39mm wide, the Jaeger-LeCoultre Master Ultra Thin Squelette isn’t exactly a bold watch, but it is in the range of what looks good on most men’s wrists as a dress watch.

Being that I was able to wear the Jaeger-LeCoultre Master Ultra Thin Squelette while at Watches & Wonders in Hong Kong, the diamond decoration feels more than appropriate, it feels downright necessary. With that said, if I had this little number on my wrist back in the states, I would still appreciate the diamonds, but I might prefer the thinner, non-set model.

One of the more interesting design elements is the ring around the exposed movement which sits under an hour marker scale and comes in a few colors. This ring is first guilloche engraved and then given an application of enamel paint. Here, you see the white version, but my favorite is the blue version (that, unfortunately, I did not get to wear, but I did get to visually inspect it – and it’s pretty cool). This design element is less about Jaeger-LeCoultre wanting to be extremely creative and more about them needing to do something with the extra space.

The problem is that the movement itself isn’t just super thin, but it is also rather narrow. That means it isn’t possible for the movement to take up too much of the case… so there needed to be a buffer zone. I actually think it would be interesting if Jaeger-LeCoultre invested in a new, wider version of this movement with some added upgrades such as more power reserve time and potentially a complication or two (power reserve indicator might be nice). Theoretically, you could keep the same thin size but just expand outwards with more parts (especially a larger mainspring barrel… or two of them).

Inside the Jaeger-LeCoultre Master Ultra Thin Squelette is the in-house made and skeletonized caliber 849ASQ. Produced from 119 parts and just 1.85mm thick(!), the movement is richly skeletonized as well as decorated with a variety of patterns and motifs on the exposed movement bridge surfaces. The movement only has 33 hours of power reserve, but that ought to get you through the black-tie event you wear this watch too.

Some of my favorite skeletonization design elements are the triple repeating “JL” motifs in the skeletonized mainspring barrel as well as the overall look and feel of the engraved decoration that looks classic, but not feminine.

One note about the skeletonization – and this might be just something with these prototype models – while the majority of the movement surfaces are nicely skeletonized, some of the rear parts aren’t really finished at all, or not finished very nicely. I get that in order for the “front” elements of the movement which are engraved to look more prominent, they should fall on a contrasting background. With that said, it appears as though some of the movement parts came right out of the machines and received little attention and perhaps no hand-finishing. Normally, that isn’t a big deal with lower-priced watches, but at this level, I expect all parts in the movement – visible or not – to be fully hand-finished and as attractive as possible. Again, this might just be an issue with the prototypes (which happens).

Legibility isn’t exactly the Jaeger-LeCoultre Master Ultra Thin Squelette watch’s strong suit, but that is to be expected with such watches. In fact, if Jaeger-LeCoultre made the hands more visible, then it would have brought attention to the fact that they don’t take up much of the dial interior, and that might have made the timepiece look odd by calling attention to disproportionate elements. Even the Jaeger-LeCoultre brand name is harder to see, being applied to the inside of the sapphire crystal over the dial. Nonetheless, when it comes to an art piece such as this, I don’t think a lot of people are looking for tool watch utility.

Every time we speak about ultra-thin dress watches of this caliber, it is important to bring up Piaget (since that is more or less one of their specialties). The Piaget Altiplano 900P (hands-on here) is the watch to beat when having an ultra thin dress watch. The Jaeger-LeCoultre Master Ultra Thin Squelette is technically thinner in its non-diamond-set form, but thicker in its diamond-set form as you see here. However, the watches are all so thin, it really doesn’t matter which one you choose if your primary concern is just to have a “ridiculously thin mechanical wrist watch.” So choose your pretty poison, even though the Piaget and these Jaeger-LeCoultre watches each have small differences.

According to the brand, the Jaeger-LeCoultre Master Ultra Thin Squelette watches are each limited to 100 pieces per version. Prices for the 18k pink gold model are $58,500 for the non-set version and $72,500 for the diamond-set version. The 18k white gold model is $61,000 for the non-set model and with diamonds, the price is $75,000. jaeger-lecoultre.com