Fox 40 Sonik Blast CMG Official Whistle 120+ Decibels of high pitch Shrill rises above ambient Noise and can be heard over a Mile away 100% constructed of high-impact ABS plastic-So they're 100% impervious to Moisture Pealess Design, No moving Parts-nothing to obstruct Sound, nothing to jam, break or freeze Ideal for large Crowd Areas such as Football Stadiums, Motorsport Race Tracks, Airport Runways, Construction Sites and any Situation where a very loud Signalling Devise is needed Fox 40 cannot be overblown-the harder you blow, the louder the Sound