Xtm Rail

What is this piece on this AR 15 Called?

I found this picture of an AR and I'd like to find a piece like the one pictured.. but I can't because I have no Idea what you call it. Its the Rubber looking part that seems to be wrapped around the mag well (I have no Idea what its for.. I just think it looks cool). Can anyone tell me what it is and maybe where I could buy one at

http://www.weaponevolution.com/forum/showthread.php?254-Magpul-XTM-Rail-Panels

Thanks

You are looking at the backside of a redi-mag

http://www.ammoland.com/2009/01/12/ar-15-m16-redi-mag-mounting-instruction-video/

Find Xtm Rail On eBay Below:



Recently Purchased Xtm Rail:


xtm hand stop handstop kit for mlok mlok rail cover