Its just a standard post. Its hypoallergenic and brand new. They are not real gold or silver, but that's all I know about it. If you use the rubber backs they sell at Walmart it would work. I have metal allergies too and use them to cover the posts on most earrings.
I have a metal allergy too. There is a seller that sells "all plastic" earrings on here that I have purchased before and they are great! What "covers" are you talking about Baggierra13? Do they slip over the post, or do you mean just the backs. Us allergy people have such a hard time finding earrings or rings. :( These are beautiful, but again, would infect my ears!!
They slip over the post and have a separate plastic end cap to fit them. Walmart carries them in the jewelry department. They run between 2 and 4 dollars for 10 pair.