V Seven 2055 Carbine Buffer Tube Lithium/Aluminum. 25 in Features: Constructed From Advanced 2055 Lithium/Aluminum Pound For Pound The Strongest & Toughest Aluminum Buffer Tube On The Planet 11 Position Mil-Spec Diameter Features Detent Lock To Prevent Tube Rotation & Carrier Support Also Features 3 Large Drain Holes Type Iii Hardcoat Anodized Weighs 3.2 Oz Package Contents: V Seven 2055 Carbine Buffer Tube What firearm models does the manufacturer say V Seven 2055 Carbine Buffer Tube is compatible with? The manufacturer says that V Seven 2055 Carbine Buffer Tube is compatible with AR-15V Seven CBT2: 2055 Carbine Buffer Tube Lithium/Aluminum