Muzzle shroud
A muzzle shroud, linear compensator, blast shield, forward blast diverter, or concussion reduction device (CRD) is a sleeve (either circular or otherwise) that attaches to and extends beyond the muzzle of a firearm in order to redirect some of the noise and concussion, or shock wave, from the muzzle blast forward and away from the anyone behind it (including the shooter) and to its sides. A muzzle shroud is similar to a barrel shroud, with the difference that it only surrounds the far end of the barrel (muzzle).