A German-made muzzle flash generator for airsoft games is now available at Blasterparts. You can order this for €74.90 and a video below shows it used in Dark Emergency 4 by Talon Company... "The Muzzle Flash Generator of Blaster Parts generates a muzzle flash in every shot of an Airsoft gun. This will make your game even more realistic. In particular, the night game is more dynamic and more demanding by a muzzle flash. You can see  where a shot came from, and you can change your game. This is what we mean by 'Advanced Combat Realism'."