The ZEV Technologies Forged AR-15 Upper Receiver comes stripped and ready for your next custom AR build. ZEV starts with high-quality 7075 T6 aluminum forgings and final machines them to better than mil-spec dimensions held to ±.001" tolerances giving you maximum compatibility with mil-spec and aftermarket parts and accessories.The ZEV Technologies Forged AR-15 Upper Receiver offers superb strength and versatility for building an AR-15 configured exactly the way you want it.