Ar-15 upper receiver stripped is a forged made out of 7075 aircraft aluminum. It’s a flat top ar-15 stripped receiver with picatinny a3 rail system to mount sights red dots or scopes. We defiantly recommend our Cerro ar-15 stripped upper receiver forging for your next build or replacing your model 1 a2 upper receiver . M4 broker stock these items and it ready to be shipped.