Shotgun

Most shotguns are tube-fed rather than magazine-fed, so this category covers two quite different things: detachable box magazines for the growing number of magazine-fed shotguns, and extension tubes that add capacity to a conventional magazine tube.

Extensions are the more common purchase and the one with a catch. The tube, the follower, the spring and the barrel clamp all have to match your specific model, and an extension that is slightly too long puts the follower where it cannot fully extend, which reduces reliability rather than improving capacity. Buy the model-specific part, not the universal one.