The Fox 40 Classic CMG is cushioned to enhance the original Fox 40 Classic whistle. The Cushioned Mouth Grip (CMG)s thermoplastic material provides superior grip and protection for teeth. Ideal for those who need to hold whistle in mouth for extended periods of time. No moving parts to freeze, jam or deteriorate. Flawless, consistent and reliable. The harder you blow, the louder the sound. Easy to blow and cannot be overblown. Chambers are designed to self-clear when submerged in water. Will be heard above ambient noise, loud crowds, the roar of engines, breaking waves and thundering gale-force winds. Sound will be heard up to a mile away.