The Spikes Tactical Forged Stripped Lower Receiver is a high-quality component for building your next AR-15 rifle. Its CNC machined construction from 7075 T6 aluminum ensures exceptional durability and strength. The Punisher Skull Logo is color-filled, adding a touch of style to your build. This lower receiver features a "Multi" caliber marking, indicating its versatility in accommodating various calibers. The low shelf for RDIAS (Rifle Defense Interface Assembly System) provides a secure mounting point for your rifle's components. Fast shipping ensures you can get started on your project quickly. Key Benefits and Features: Material: 7075 T6 aluminum Caliber marking: Multi Finish: Type II hard coat anodized Color fill: Punisher Skull Logo Low shelf for RDIAS: Yes Accepts trigger pins diameter: .154"