WORKHORSE Forged 7075-T6 Lower ReceiverSpecifications: Quality Aerospace 7075-T6 Aluminum Alloy MIL-A-8625F, Type III, Hard Anodized Flat Black Finish Compatible with TDP/Mil-Standard AR Lower Receiver Parts Broached Magazine Well Pictograph Selector Markings Properly Marked for 90deg Safety or Short Throw Safety Selectors Multi-Caliber Marking for Build Versatility Captured Takedown Pin Detent Spring (Set Screw Included) 4-40 Upper/Lower Receiver Tension Screw (Screw included) Made in the USAFEDERAL FIREARMS LICENSE REQUIRED