American Built Arms Company Buffer Tube Assembly Black. Specifications for American Built Arms Company Buffer Tube Assembly: Manufacturer: American Built Arms Company Color: Black Finish: Anodized Fabric/Material: 6061-T6 Aluminum Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Length: 7.125 in Diameter: 4.5 in Features of American Built Arms Company Buffer Tube Assembly MilSpec buffer tube designed for the AB Arms MODX receivers and adapters Receiver extension has six adjustment holes Package Contents: American Built Arms Company Buffer Tube Assembly Castle Nut What firearm models does the manufacturer say American Built Arms Company Buffer Tube Assembly is compatible with? The manufacturer says that American Built Arms Company Buffer Tube Assembly is compatible with AR-15American Built Arms Company ABABTA: Buffer Tube Assembly Black