Although similar, I do not feel that this is a WMF product. I am unaware that Zwiesel made vases shaped like this, but do not know with certainty. Additionally, given that the products of both of those manufacturers tend to be "cluthra" types of glass, and that this vase is monochrome, without any bubbles, again causes me to doubt them as the source. The base of this vase looks very much like the Lausitz wares shown in the book. I'll have to see if I can dig up the title of the Lausitz book, but it will take a while.