HUXWRX' 5.56 bore alignment rods ensure proper concentricity and alignment of the suppressor and muzzle device along the bullet trajectory to prevent misalignment and strikes. It is recommended that barrel-to-suppressor alignment be verified on any build before it is first fired. Currently, HUXWRX offers bore alignment rods in three calibers: 5.56, 7.62, and .338.Specifications:Material: Carbon FiberStraightness: 15 in / 38.1 cmHazmat FalseThreaded Barrel False