The Geissele Premium AR-15/M4 Mil-Spec Buffer Tube is a great way to ensure the stability of your AR-15. This AR-15 Buffer Tube manufactured by the experts at Geissele is machined from quality 7075-T6 aluminum and finished in Type 3 hardcoat anodize. This Geissele Premium AR-15/M4 Mil-Spec Buffer Tube features 6 stock positions and conforms to all Mil-Spec standards. The Geissele AR15/M4 Mil-Spec Buffer Tube is the perfect fit for your AR-15 lower and compatible with most carbine length and mil-spec diameter AR-15 stocks. This Geissele AR-15/M4 Mil-Spec Buffer Tube is included in the package are a high-quality, mil-spec castle nut and end plate that are sure to provide years of reliability and performance. Specifications for Geissele Premium Mil-Spec Buffer Tube: Manufacturer: Geissele Finish: Type 3 Hardcoat Anodized Fabric/Material: 7075-T6 Aluminum Gun Make: AR Platform Gun Model: M4, AR-15 Gun Type: Rifle Condition: New Country of Origin: USA Package Contents: Geissele Premium AR-15/M4 Mil-Spec Buffer Tube What firearm models does the manufacturer say Geissele Premium Mil-Spec Buffer Tube is compatible with? The manufacturer suggests that Geissele Premium Mil-Spec Buffer Tube is compatible with AR-15, M4