1999. “flash suppressor” means any device that reduces or conceals the visible light or flash created when a firearm is fired. This definition includes flash hiders, but does not include compensators and muzzle brakes (devices attached to or integral with the muzzle barrel to utilize propelling gasses for counter-recoil). ↑ Dinan, Elizabeth (10 April 2014). "SIG Sauer sues ATF for calling its 'muzzle brake' a gun silencer".