The Mesa Tactical Magazine/Barrel Clamp for tactical shotguns is a two-piece clamp made of 6061-T6 aluminum which is lightweight and sturdy. The Mil-spec Type 3 hardcoat is anodized to withstand hard use.
So, what is the purpose of the barrel/magazine clamp? It holds the magazine extension more securely to protect it from damage in case of bumps. Hits are very common when you actually use your shotgun for hunting, training or home defense. Just remember that if you hit something with your magazine extension and it brakes, then the spring, follower and all the ammo will just fall out of the magazine tube. If the magazine tube nut stays in place, then you will be able to put your shotgun loading rounds into a chamber. But if the magazine extension and magazine tube are broken, the barrel will not stay in place while making the shotgun useless.