This typewriter uses a type wheel that can be switched with another to change the font. When typing, a spring loaded hammer behind the carriage swings forward and strikes the paper and ribbon against the type wheel.
The flat metal holder on top of the lefthand ribbon spool holds a fountain pen, allowing the typist to make horizontal or vertical lines by moving the carriage sideways or the paper up and down. A pen is shown, held in this clip, in the second image below.
The last image below is a fantastic illustration from the cover of the manual.
This typewriter originally sold for $50.00.