The Tank Must Watch 31mm in Steel with Leather Strap Watch by Cartier from the Tank collection. Paired with a calf skin strap and deployant clasp, this watch features an automatic (self-winding) movement with date in aperture, and seconds hand complications. A silver opaline colored dial with blued-steel hands complete the look. This watch has 30 meters water resistance. This watch has 3 atmospheres water resistance.