I own a big old,old parallel drafting rule and a small one that is about
the size of a legal note pad.It has a hole in the middle of the cover
(sort of like the front of a hard back book) for the knob that lossens
and tightens the L shaped rule to fit through when the cover is
closed.The L shaped rule can be adjusted to any angle desired by
loosening and tightening the knob.It is a very handy little device for
drawing straight parallel lines on paper.I bought them at the Goodwill
store about ten years ago.I am not going to remove the cord (I didn't
know there is a cord in there) out of my big old parallel rule though.I
dont think my small parallel notebook size parallel rule drafting device
has any cord in it.They bough still work just as good as the day they
were made,perfect parallel lines.
cuhulin