Worn by Louis Cartier himself, the "Tank Louis Cartier" watch sets the standard for all Tank watches. To embody Louis Cartier's contribution to "modern style", later known as Art Deco, the tops of the lugs were rounded in contrast to the previously fashionable rectangular form and proud lines.

Case in 18K rhodiumized white gold set with brilliant-cut diamonds, beaded crown set with a brilliant-cut diamond. Mineral crystal, silvered grained dial, Roman numerals, blued-steel sword-shaped hands. Alligator strap. Workshop-crafted mechanical movement with manual winding caliber 430MC, water-resistant to 20 meters. Case dimensions: 40.40 x 34.92 mm, 5.1 mm thick.