I think he’s talking about the shroud.

The barrel shroud is a safety feature that keeps you from burning yourself from a hot barrel. It is suspended around the barrel and doesn’t heat up. If you are at the range and shooting, barrels can get quite hot.

Also a convenient place to attach things to like a forward grip or a flashlight etc.

Ironically, this safety feature is often mentioned as a characteristic of an “assault weapon” by those seeking to ban rifles. It is simply a safety feature for the operator.

I think he’s talking about the shroud.

The barrel shroud is a safety feature that keeps you from burning yourself from a hot barrel. It is suspended around the barrel and doesn’t heat up. If you are at the range and shooting, barrels can get quite hot.

Also a convenient place to attach things to like a forward grip or a flashlight etc.