Plastic Piece/Spring on top of Fireplace???

Guys,

I just bought a house and the wood burning fireplace was brought up to code with a stainless steel liner, chimney repaired and firebricks installed. There is a black piece installed at the top of the fireplace that i don't know what it is? Can anyone take a look and see if it is required for me to leave there or can I remove it? It looks like some type of spring for more support possibly. I did a quick google search and couldn't find anything?

Thanks,
Ryan