TubeNet

I don't understand a word of German (that's German, isn't it?) but it cought my eye. Is that a F tuba? Or may-be an Eb with that twisted slide... I don't know...

http://cgi.ebay.es/alte-Tuba-Buegelhorn ... dZViewItem

tuba by Julius Rudolph, Gotha (father, son, grandson) 1880-1945

extra slide looks like Low Pitch (about 1/2 step)