Editorial
If you want a dress watch on a leather strap, the Tank Louis Cartier is the answer. Designed in 1922 (a direct evolution of Louis Cartier's original 1917 Tank), the LC is the cushioned, gold-cased, narrow-lugged variation that defined what a dress watch should look like for the next century. Current production is hand-wind, 33mm, on Cartier-supplied leather, with the iconic blued sword hands.
The Tank itself dates to 1917, inspired by the silhouette of Renault tanks; the 'Tank Louis Cartier' variant launched 1922 and has been continuously produced since (with quartz, automatic, and hand-wind movements in different generations). The current production reference (WGTA0011 in pink gold, WGTA0017 in white gold) is hand-wind via Cartier's 1917 MC caliber. There are larger and smaller sibling variants; the 'Tank LC' designation in collector usage almost always refers to the 33mm dress-proportioned version on a leather strap.
Common things to check: case material (the pink-gold and white-gold versions trade at very different price points; verify hallmarks on the case-back); dial originality (refinished Cartier dials are spotted by the printing of the 'Cartier Paris' or 'Cartier' wordmark, the typography is unmistakable when original); strap and buckle (Cartier-supplied straps are leather + tang buckle in matching metal; replacements are common and acceptable but should be priced accordingly); crown (a sapphire cabochon, often blue, sometimes replaced, replacement is acceptable if disclosed). Vintage Tank LCs (pre-1990s gold-cased manual-wind examples) require additional dial and movement-authenticity verification.