JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position Black. Machined with ten recessed channels that provide both weight and friction reduction this buffer tube will allow even the tightest Mil-Spec stocks to slide with ease. Specifications for JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position: Manufacturer: JE Machine Tech Color: Black Finish: Anodized Fabric/Material: 6061 Aluminum Gun Make: AR Platform Gun Model: AR-15 Length: 7.15 in Diameter: 1 in Features of JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position 3 drain holes for marine environments Recessed pockets for weight reduction Accepts all Mil-Spec stocks AR-15 & AR-10 compatible Package Contents: JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position None What firearm models does the manufacturer say JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position is compatible with? The manufacturer says that JE Machine Tech AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position is compatible with AR-15JE Machine Tech PS-BTMS6: AR15/M4 .223 Mil-Spec Recessed Buffer Tube 6 Position Black