Housed in a 39.7 mm 18K yellow gold (750/1000) case, the Santos de Cartier WHSA0042 keeps the model's signature square silhouette and exposed screws intact. The 7-sided crown is set with a faceted sapphire, and gold-tone sword-shaped hands sweep across the open-worked dial, where the bridges themselves are shaped into Roman numerals — a detail that merges legibility with mechanical display.
Powering the watch is the manual-winding skeleton caliber 9612 MC, its gear trains and spring barrel visible through both the sapphire crystal and the transparent case back. A 72-hour power reserve carries the watch well through a long weekend, while water resistance to 100 meters adds a layer of everyday practicality. The movement comprises 138 parts, each on show through the openworked construction.
Versatility is built into the package: the yellow gold bracelet uses Cartier's SmartLink system for tool-free size adjustment, while the included grey alligator leather strap with QuickSwitch technology allows for a rapid change of character. A folding buckle secures the leather option. Together, the two wearing options give the WHSA0042 a range that stretches from formal occasions to a more relaxed daily context.
