Versatile, Lightweight, Strong, Smooth Function, and Stylish! TacStar’s modular shotgun extension tubes provide all of these benefits, while adding additional capacity to your shotgun. The tubes are machined from tough 6061 aluminum, anodized matte black, and include a recess for a magazine/barrel clamp. Since both ends of the modular design tube have the same thread, it can be reversed to change the location of the recess for maximum versatility.