ID shotgun parts

[GuiltySpark]

Hey dudes,

I was wondering if you could help me identify some parts on this shotgun for a friend of mine. I'm not really a gun parts guy so I have no clue. Could someone ID the stock, rail system and forearm? (optics aren't an issue)

 

[badboybeeson]

First gen ar15 870 cqb stock adaptor
Kac Ras gen 1. Discon.
Surefire 618da forend light

The stock adapter and long rail has been made by us for the last 7 or so years
Can be found on our website.
Bbb

 

[GuiltySpark]

Awesome thanks a lot.