Closet metal bi-fold door part

A handy person from Allen Park, MI says:
I believe that I need part # 21-100.... a nylon guide post cap. However I am not totally sure that this is the correct part. The pictures that are included shows the two posts, the pivot post has a smaller diameter cap, which I do not need. I do need the nylon cap that is on the larger diameter guide post. I do not have a model number for the door as it is quite old and was already here when I moved in.
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Paul from SWISCO responded:

Greetings from Without knowing the measurements or diameter of the part you are looking to replace, we can not give a precise suggestion. We have placed a list of possible replacement caps in a list on this page for your review. Look each one over thoroughly to see if any of these are a match.

Bi-fold Door Repairs
Bi-fold Door Repairs
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