Hardware for metal bifoldeing door

We may be able to supply a match for this pin, but we need more information. Can you tell me the diameter of both the metal pin and the nylon cap? The diameter for the cap I need is the skinny part that goes into the track, not the "brim" so to speak. 

Can you also tell me if you see any brand names or markings on your door? It would be a huge help if you can find anything that may indicate who made these.