Cartier Tank Basculante 150th anniversary 18K yellow gold Among the Tank models by Cartier, the Tank Basculante is considered the most intriguing. • When the dial is pulled out, we can see a complex "cabriolet" mechanism that allows the dial to flip over, revealing the back of the watch. • Early models were often referred to as "Tank Cabriolet" or "Reversible Basculante," which are particularly easy to spot in old auction catalogs. • When Cartier began reproducing this model in larger quantities in 1999, they standardized the name as "Tank Basculante." • The Basculante utilizes a unique cabriolet system (French for "convertible") to flip the dial. • This flipping mechanism was developed by Spécialités Horlogères, the same company that developed the sliding case mechanism for the Reverso, later integrated into Jaeger-LeCoultre models. • The lever to pull the dial is positioned at 6 o’clock, and modern versions often feature a cabochon or a ruby set in this position, allowing the back of the case to flip upward. • By keeping the hinges in a half-locked position, the Basculante can transform into a small, elegant desk clock. • In 1997, to celebrate the brand’s 150th anniversary (1847-1997), Cartier produced: 150 pieces of the Tank Basculante in 18k gold, 150 pieces with diamond-set bezels, and 15 pieces with skeletonized movements visible from the back. +/ Technical specs of the Cartier Tank Basculante 150th Anniversary • Case: Made from 18k gold with a diamond-set bezel. • Dimensions: Perfectly proportioned at 37 x 23mm and with a thickness of only 5.8mm. • Cabriolet Mechanism Frame: Contains a red ruby cabochon, unlike the usual blue cabochons, marking the first indication that this is no ordinary Basculante. • Dial: Displays Cartier’s signature classic Roman numerals around a rectangular dial. The center is engraved with the Cartier logo, instead of the guilloché patterns commonly seen in standard models. Combination of “Cartier” and “Paris” on the dial highlighting the brand's distinct sophistication. • Hands: Blued sword-shaped hands, contrasting beautifully with the silver-white dial, enhancing the watch’s timeless and elegant look. • Movement: Equipped with the Cartier 161 manual-winding movement, based on the Piaget 40P caliber. The movement operates at a frequency of 21,600vph and offers a power reserve of approximately 36 hours. • Caseback: Features the brand’s logo, the limited-edition number, and the inscription "Made in France." Its elegant, refined appearance, combined with a touch of luxury, has captivated enthusiasts and is highly sought after by collectors worldwide.