166665

Cartier Tank Basculante ref W1011158 is a fascinating edition of the broader Tank collection because it features a vertical flipping case hence the model name which translates to "seesaw" or "tipper."  It works via a convenient "cabriolet" system developed by Spécialités Horlogères that allows the wearer to flip the watch face upside down to reveal the case back by pulling on the blue cabochon tab at 12 o'clock. This design was initially meant to protect the watch during sports and was developed by the same company as the famous Reverso Jaeger-LeCoultre. In fact the original model was released in 1933 just one year after the Reverso came to market. The aptly named "cabriolet" (a French term for convertible) can also remain upright essentially turning the watch into a tiny desk clock.  Production was intermittent until around a decade ago when the watch also commonly called the Tank Cabriolet or Reversible Basculante was finally discontinued.  We have a remarkable example for sale here today in stainless steel featuring a 22MM x 25MM case and a quartz movement.