That would most likely be the 20th Division. "Husaron" should be "Husaren," auf Englisch, "Hussars." You do not say what the dates on the Karte are, so I'm assuming it is the First World War or before. The unit was raised in Braunschweig. I wish I could be of more help, but all my military links seem to be outdated and regrettably, none of my references are so recent.