I came across a rather Dallmeyer 2A lens. I have not been able to come across alot of info on the beast. Beyond that I will admit, I know next to nothing about this monster, I am not sure whether I will keep it or get rid of it. But, if anybody has information on this thing it would be greatly appreciated. What I do know is it's 20.5cm(8.1in) long, 11.8cm(5 inches) in diameter, and it weighs 2120grams (4.6lbs). Its in good condition, the focusing knob is smooth, the glass is scratch free and there is no fungus or any other artifacts. There are no waterhouse stops or flange. Attached below are a couple of pictures.