Ensure prefect concentricity between your suppressor and host weapon with SureFire's Bore Alignment Rods. Precision machined from heat-treated stainless steel, the Bore Alignment Rod closely resembles the flight path of a bullet and will show any misalignment. This is perfect for confirming proper alignment on new platforms prior to firing the first round. Additionally, the Bore Alignment Rod is available in 5.56mm, 6.5mm, 6.8mm, 7.62mm, 9mm, .338 cal. Features of the Bore Alignment Rod: Precision machined rods for most accurate verificationFor validation of set-up prior to first round firedSpecific caliber rods for the most popular options on the market todaySimply insert rod through the mounted suppressor of an unloaded weaponEqual space should be seen between bore of suppressor and centered rod Surefire 5.56 Bore Alignment Rod SF-ROD-556