It's a Steam Support-duped medal. Interesting, though, as I always thought that medals that were duped by Steam Support would maintain their numbering. I'm not sure if it's a glitch that it has no number, or if that's normal for duped medals.

But I feel that it's important to note the fact that this is, in fact, a duped item.
 
The item has no previous owners, though. It was duped by Steam Support directly into your backpack.

Unless Steam Support is wiping the trade history on duped items or something.
 
if it was duped it would have the same number? ne? this is a NEW item and not to sound rude but id appreciate it if you didnt try to scare off potential buyers.
Have a wonderful day~