Above is a picture of the lower pin slider for the Buchmin Industries mirrored bi-fold door.
A handy person from Hawaii says:
September 11, 2021
I would like to purchase four parts.
Paul from SWISCO responded:
September 16, 2021
Thank you for your patience during our busy season. Your nylon roller guide looks like our 21-174 that fits into a track like the 21-452 . Look these over and compare our dimensions to yours to see if these could be what you need.