Yankee Hill Machine Low Profile Flash Hiders offer the same great performance as the Phantom Flash Hiders, eliminating 99% of the visible muzzle flash. Their low profile design allows a gas block with an inside diameter of 0.75" to be installed and uninstalled without the removal of the Flash Hider. The Low Profile Flash Hider's small outside diameter is great when pinning and welding the Flash Hider on a 14.5" barrel. Since it allows both the gas block and the handguard to be installed directly over the Flash Hider.