Fox 40 Classic CMG Official Finger Grip Whistle The compact Mini whistle's 109 Decibels of high pitch shrill rises above ambient noise-can be heard up to a mile away 100 percent constructed of high-impact ABS plastic-So they're 100 percent impervious to Moisture Pealess Design, No moving Parts-nothing to obstruct Sound, nothing to jam, break or freeze CMG made of Thermoplastic is preferred by Officials who hold the Whistle in their Mouth to assure a secure Grip Fox 40 cannot be overblown-the harder you blow, the louder the Sound