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, with an Open Trigger. Technical Specifications Receiver Finish Type 3 Hard Anodized, Black Lower Receiver Material Forged 7075 T6 Aluminum Trigger Guard Open Trigger Compatibility All AR15 Platform Calibers Weight 0.68 Country of Manufacture USA UPC 711841564742