The Battle Arms Xiphos AR9 AR-15 Stripped Receiver Set is Precision CNC from Billet 7075-T6 Aerospace Aluminum. FeaturesPatent Pending Lightweight DesignLaser Engraved LogoMIL-A-8625F, Type III, Class 2, Hard Anodized Black FinishCompatible with TDP/Mil Standard AR Lower Receiver Parts Dimensional Accuracy InspectionAll Sharp Edges De-Burred Sharp by HandPictograph Selector Markings Properly Marked for 90deg Safety or BAD-ASS-ST / BAD-CASS-ST Short Throw Ambidextrous Safety SelectorsReceiver Safety Selector Hole & Internal Wall Machined with Relief Cut for Battle Arms Development "SHORT-THROW / REVERSIBLE" Ambidextrous Safety SelectorsMulti Caliber Marking for Build VersatilityFlared, Deep Beveled Magazine wellEasy in Install Set Screw Bolt Catch Pin (Pin Included)Captured Takedown Pin Detent Spring (Set Screw Included)Upper/Lower Receiver Tension Screw (Screw included)Integrated Trigger GuardAll Components, material, and packaging made in the USAMRB (Magazine release block) conversio...