The WSSA0029 is the medium steel Santos de Cartier, since 2018 the more compact counterpart of the large WSSA0018.
The design is the same: a square case with rounded corners, a bezel with visible screws running into the lugs, a silvered dial with Roman numerals and blued steel sword hands, and a crown with a cabochon. The case measures 35.1 by 41.9 mm and therefore wears noticeably smaller.
This model also has the automatic calibre 1847 MC, with a power reserve of about 42 hours. The steel bracelet has SmartLink so that it can be sized without tools, and QuickSwitch lets you change to a leather strap without tools.
On a pre-owned example we check the same points as on the large Santos: the polished bezel and its screws, the transitions between polished and brushed surfaces on case and bracelet, the working of the exchange and sizing systems, and the cabochon on the crown.
We state which straps and links are included and whether the box and guarantee card are present. If you are torn between the two sizes, bear in mind that a Santos wears larger than its width alone suggests, because the lugs continue the line of the case.