Geissele Premium Mil-Spec Buffer Tube Assembly With Super 42 H37075-T6 AR-15/M4 Black. Geissele machined these AR15 Buffer Assemblies from 7075-T6 aluminum and added a Type III hard coat anodized finish to further enhance their strength and resistance to corrosive elements. This Geissele Premium Mil-Spec Diameter Buffer Tube Assembly w/ Super 42 offers six stock positions to meet your preferences. The Super 42 Spring is made from three independent wire strands which efficiently absorbs energy greatly reducing the chance of spring failure. Enhance your weapon build by swapping in the Geissele Premium Carbine-Length MIL-SPEC Buffer Tube with Super 42. Specifications for Geissele Premium Mil-Spec Buffer Tube Assembly With Super 42 H1: Manufacturer: Geissele Finish: Type 3 Hard Coat Anodized Fabric/Material: 7075-T6 Aluminum Gun Make: AR Platform Gun Model: M4 AR-15 Condition: New Weight: 3.7 oz Country of Origin: USA Features of Geissele Premium AR-15/M4 Mil-Spec Buffer Tube Assembly w/ Super 42 Spring: Machined from quality 7075-T6 Aluminum Finished in Type 3 Hardcoat Anodize 6 stock positions Unique spring design uses three independent strands of wire The Super 42 Spring has a 15percent stronger average return force than the standard buffer spring Package Contents: Geissele Premium AR-15/M4 Mil-Spec Buffer Tube Assembly w/ Super 42 Spring What firearm models does the manufacturer say Geissele Premium Mil-Spec Buffer Tube Assembly With Super 42 H1 is compatible with? The manufacturer suggests that Geissele Premium Mil-Spec Buffer Tube Assembly With Super 42 H1 is compatible with AR-15 M4Geissele 08-163B-H3: Premium Mil-Spec Buffer Tube Assembly With Super 42 H37075-T6 AR-15/M4 Black