Watchuwant is now WatchBox! Subscribe for the best luxury watch content. JLC Master Ultra Thin Reserve de Marche Review Jaeger-LeCoultre is no stranger to the automatic watch/power reserve combo. Since 1948, this tandem has been a specialty of the manufacture from Le Sentier, and the new Jaeger-LeCoultre Master Ultra-Thin Reserve de Marche takes tradition to the next level. Introduced in 2012, the newest generation of JLC Master Ultra Thin cases combine serious refinement with equal measures of substance. While the old-school JLC "Powermatic" power reserve models of the Ike Era measure 31-36mm, the modern Jaeger-LeCoultre Master Ultra Thin Reserve de Marche enters the 21st century with broad-shouldered authority. Less than 10mm thick, the wrist presence of this watch is elegant but never quaint; a 39mm diameter ensures that nobody mistakes this modern marvel for a petite vintage bauble. Jaeger-LeCoultre's caliber 938 features all of the hallmarks of a manufacture par excellence; ceramic rotor bearings; high-efficiency unidirectional winding; sub-5mm thickness, and laser-welded hairspring. It's fine, slim, and still everyday tough; think Karen Allen in "Raiders of the Lost Ark," and you get the idea. JLC's Reserve de March took a huge aesthetic leap forward with the Ultra Thin model. The 2000s were a time when big was better and huge was best. Even dress watches were overtaken by the tide, and Jaeger-LeCoultre's Master Reserve de Marche featured more mass and volume than many dress watch enthusiasts preferred. And those days are history; JLC's new Master Ultra Thin case isn't slightly smaller in diameter, it's dramatically better-sculpted and pared down to the essence of elegance. If the 2000s model was a defensive lineman in a suit, the new Ultra Thin RDM in stainless steel is a lithe wide receiver in tailored duds. And JLC adds to the glory of this perennial all-star; the power reserve gauge, radial date, and small seconds provide both calculated asymmetry and real utility to the owner. Short of the hours and minutes, is there any more pertinent info to the user of a watch than seconds, date, or hours of movement function remaining? See this Jaeger-LeCoultre Master Ultra Thin Reserve de Marche on https://www.thewatchbox.com/watches/jaeger-lecoultre Instagram: https://www.instagram.com/watchbox/ WatchBox Reviews Channel: https://www.youtube.com/WatchBoxReviews Video and content by Tim Mosso.