Cf. A. Triossi, Between Eternity and History, Bulgari, from 1884-2009, 125 Years of Italian Jewels, Skira, Milan, 2009, p. 149

This ring is a variation of the classic 'Trombino' model first introduced by Bulgari in the early 1930s. In this later design the baguette-cut diamonds are set vertically as opposed to the horizontal settings of the earlier Art Déco editions.