I think its a Rock River upper that isn't made any more. The hole in the side is for battery storage but I never had the cap. I am sure one could be fabricated or maybe rock river has them. No forward assist or port door assembly.
$50 shipped to your door. Money order or cashiers check please. First to post "I'll take it" gets it. Follow up with an email to me at firstname.lastname@example.org
SOLD PENDING FUNDS