The Packaged AR-15 Stripped Lower Receiver is American made with superior quality for less. Anderson's lower receivers are CNC machined from a high-strength, 7075 T6 aluminum forging for reliable performance and outstanding durability. Machined to military specifications & standards and marked "Multi-Cal" to be used with multiple calibers on the AR-15 platform. This Lower Receiver comes in type III black hard anodize, and an Open Trigger.