metal bi fold door.
A handy person from howland ohio says:
November 30, 2014
My metal bi fold doors I think have some worn parts. The one in bathroom get messed up occasionally and I have to put back on track. The spring is bent and the bottom plastic piece looks worn. Looks like I need one spring, maybe a few bottom plastic runners or what they are called. Maybe a end stop.
Dave from SWISCO responded:
December 3, 2014
Take a look at our 21-044 pin with clip. I believe that is the part you are looking for.