Our recoil tube is made from 6061- T-6 and hard black anodized. We also precision hone the inside diameter of the tube for a super smooth buffer and spring movement. The tube uses a standard end plate and nut. No need to modify the end plate. When installed the tube extends 9.5″ when measured from the end plate. This makes the tube flush with the back of the arm brace for a more solid feel. Other tubes require a sleeve to be added if you want to move the arm brace back for folks with longer arms. Ours is machined as part of the tube. Available with end plate and castle nut. Also available with standard buffer and chrome silicone spring. Weight is 7.1 ounces.