This whistle is truly remarkable! It is the highest-selling whistle of all time, and its convenience, small size and high pitch (117dBA) make it loud enough to be heard in any situation. Customers love using it in colder settings, as metal won't stick to the skin; but it's also popular among sports officials, teachers, animal trainers, police, military personnel and music experts. It's especially great for people who struggle with breathing, as well as for young and elderly people who need a safety whistle. Plus, this whistle has been used to referee FA and World Cup finals! With over 30 million sold worldwide, its power and reliability is proven.