The Cartier Ronde Must de Cartier WSRN0031 is the 36mm stainless steel round-cased dress watch that anchors the entry to Cartier's Ronde collection, and the sandblasted silvered dial configuration is among the most classically Cartier expressions of the modern round dress watch. The Ronde de Cartier silhouette descends from the early-twentieth-century Cartier round wristwatches that ran in parallel with the Santos and Tank lineages, with the Ronde Must positioned as the modern, accessibly priced re-expression of that classical round profile. The 36mm stainless steel case measures just 7.89mm thick, sitting flat under any cuff and wearing as comfortably for daily use as for formal occasions. The sandblasted silver-tone dial features the blued sword-shaped hour and minute hands, a black inner railway minute track, and the Roman numerals around the chapter ring that have become the visual signature of Cartier's round dress watches. Sapphire crystal, the beaded steel crown at 3 o'clock set with a synthetic spinel cabochon, fitted to a black leather strap with steel pin buckle. Powered by a high-autonomy Swiss quartz movement with up to approximately 8 years of battery life. Water resistance to 30 meters. Pre-owned.