Apple in ear headphones w/ mic model number question

I just purchased the Apple in ear headphones w/ mic from Amazon. They have the model number listed as MA850G/B, the same that is listed on Apple's website. Well, when I received the order today, the model number was MA850G/A, on the package. Should I return these, or are these headphones the same? I tried calling Apple help and asking them, and they couldn't find an answer. I'm figuring that their just an older model, but who knows. Any advice or comments appreciated.


Terry