Was there a chocolate bar called duet?

There was a chocolate bar called Duett, which was produced by the German chocolate company Stollwerck. It was a milk chocolate bar with two distinct flavors, with one side being hazelnut-flavored and the other side being caramel-flavored. The Duett bar was introduced in 1931 and became one of Stollwerck's most popular products, particularly in Germany and other parts of Europe. The bar gained notoriety for its unique combination of flavors and for being a pioneer in the concept of dual-flavored chocolate bars. However, the Duett bar was discontinued by Stollwerck in the early 21st century, and it is no longer available on the market.