Aero Precision APCS308159: Aero Precision's M5 receivers are engineered to match flawlessly, providing the operator superior performance and accuracy in a durable and dependable platformUpper Receiver Features: Platform: M5 (.308) Material: Machined from 7075-T6 forged aluminum Coating: Matte black hard-coat anodized Mil 8625 Type 3 Class 2 M4 Feedramps .2795" takedown pin holes (DPMS size) AR 308 High Profile (.210) Tang Accepts standard DPMS .308 components Laser engraved T-marks Includes Port Door and Forward AssistLower Receiver Features: Platform: M5 (.308) Material: Machined from 7075-T6 forged aluminum Coating: Matte black hard-coat anodized Mil 8625 Type 3 Class 2 Markings: "Cal Multi" Works with standard DPMS 308 components and magazines Rear takedown pin detent hole is threaded for a 4-40 set screw Bolt catch is threaded for a screw pin (no roll pin needed) Integrated trigger guard Selector markings will work with 45, 60 or 90 degree safety selectors Accepts Battle Arms Development short throw safety selectors, but will work with any standard selector No gap with aftermarket pistol grips