Jaeger-LeCoultre would like to remind you that it’s not just all about the Reverso in Le Sentier. Case in point, a subtle update to the Master Ultra Thin Power Reserve reminded me how the company that used to be nearly everyone’s go-to movement supplier hasn’t stopped making technical improvements to its great watches.

The new Jaeger-LeCoultre Master Ultra Thin Power Reserve might not look that different. Cased in 18k pink gold, the blue sunray-finished dial is pretty striking. The case still measures 39mm by 8.95mm thick, but it now has revised proportions, with slightly elongated and slimmer lugs. It’s what’s inside that’s revamped more dramatically. The last iteration of the Caliber 938 movement had 43 hours of power. With only minor changes – a redesigned mainspring barrel and some key components made of silicon – JLC has reduced friction in the movement and now gets 70 hours out of the caliber.

I don’t think Jaeger-LeCoultre Master Ultra Thin Power Reserve gets enough attention for their work with ultra-thin watchmaking. Maybe that’s because a dress watch like the Jaeger-LeCoultre Master Ultra Thin Power Reserve might not be, on its face, the most creatively exciting watch from a design standpoint. It’s not bold or brash, but it sure looks like it could be quite attractive.

I say it could be because I haven’t seen it in person yet. I can’t tell much about the finishing on the movement from these images, but judging by past experience with Jaeger-LeCoultre Master Ultra Thin Power Reserve watches, I have a feeling it doesn’t disappoint. Whether or not you like the power-reserve dial, with date, small-seconds, and power reserve kind of creating an interesting off-balance design, is personal taste. But 8.95mm with a 70-hour power reserve is nothing to scoff at – in fact, it’s an impressive upgrade over the past release’s 43 hours.

Unfortunately, right now, the new updated Caliber 938 only seems to come in Pink Gold, not steel, so the price feels a little steep. Compared to something like a Vacheron Traditionelle Self-Winding, however, it’s less than one millimeter thicker, has 30 hours more power reserve, and costs $9,000 less, making it a pretty strong option. Hopefully I’ll get to handle one soon and see how it holds up in the metal.