Manufactured in the 1950s, this is an exceptionally rare Cartier “Tank Duoplan” rectangular model in 18K yellow gold, powered by the EWC (European Watch & Clock Company) Cal. 409 movement with a back-wind configuration. Among the already scarce EWC movements, the Cal. 409 is particularly rare as a back-winding movement. The distinctive case shape—often referred to as the back-wind or “bec d’aigle” (eagle beak) design—gives this piece a striking presence, standing out even within the many variations of the Tank line.
The Tank Duoplan was produced in multiple sizes for both ladies’ and men’s models; this example is the large size, measuring 22mm in width and 33mm in length. It is accompanied by a valuable original fixed 18K yellow gold deployant (D) buckle. The current wrist size is set to approximately 17cm.