This is a beautiful 1970's mid size Cartier Must de Cartier vermeil tank watch. This watch is manually wound. The outstanding feature of this example is its real lapis stone dial. 

The case of this watch is 23.5mm x 30.5mm which is considered Cartier's mid size tank. It is the perfect unisex watch. The case condition is excellent, showing no signs of gold loss. 

There are few equal examples of classic mid century design than Cartier's tank watches. Greta style and great investment.