Guntec USA AR 9mm Cal MIL-SPEC Buffer Tube Set Anodized Black. 9 oz Features of Guntec USA AR 9mm Cal MIL-SPEC Buffer Tube Set Six Position Buffer Tube Package Contents: Guntec USA AR 9mm Cal MIL-SPEC Buffer Tube Set End Plate Castle Nut 9mm Cal Buffer ChromEnd Plate Castle Nut 9mm Cal Buffer Chrome Silicon Coated Springe What firearm models does the manufacturer say Guntec USA AR 9mm Cal MIL-SPEC Buffer Tube Set is compatible with? The manufacturer says that Guntec USA AR 9mm Cal MIL-SPEC Buffer Tube Set is compatible with AR-15Guntec USA MILTUBESET-9: AR 9mm Cal MIL-SPEC Buffer Tube Set Anodized Black