Kugelhopf pans are essentially the same as fluted tube pans. They are used to make kugelhopf cakes.
The tube in the middle allows heat to penetrate cake from the centre in.
The fluted design of the edges allows for more surface of the cake to get browned, while also allowing more heat to penetrate into the cake for better cooking.
The pans come in various sizes, even mini-sizes.
They will be made of heavy-gauge steel, aluminum, glazed clay or ceramic, or non-stick metal.
Early versions were ceramic and earthernware. In the 1880s, they were made of tin-lined copper. They were introduced into America under the trademarked name of Bundt pans.