3-chamber pealess; smaller mouthpiece Sound Power: 109 decibels The best personal security whistle out there! An effective safety and protection device. The Fox 40 will be heard above ambient noise, the roar of engines, breaking waves and thundering gale-force winds. The chambers are designed to self-clear when submerged in water. There are no moving parts to freeze, jam or deteriorate. The Fox 40 Mini is a smaller version of the Classic Whistle. The compact design of the Mini easily fits into a pocket or purse and is an excellent personal security whistle. The Fox 40 is so effective and so easy to carry and use that people around the world are finding new applications for it almost every day.