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. Tank Louis Cartier watch, small model, quartz movement. 18K yellow gold case, beaded crown set with a sapphire cabochon, silver-grained dial, blued-steel sword-shaped hands, mineral crystal, alligator-skin strap 18K yellow gold ardillon buckle.