The Kiwis are having all the fun with BLTech's Gun Sound Simulators which they call B.O.S.S. In this video of an airsoft base assault. There are more BOSS units in play including one mounted on an M249. Just listen to the sound of battle and take note that only 5 of units were being used. Just imagine a big milsim event where everyone is equipped with one. Event organisers must plan to use these where the local population would not complain. This innovation gives you gives some more tensioni in the game as the sound of warfare just became so real in airsoft.