I bought this pipe as a teacher, not only to whistle sports games, but also to draw attention to me in the hall, on the sports field or possibly even time in the classroom. Grade latter works hereby really great, because after a (even tentative) whistle in a closed room all need including myself first quarter of an hour to get the hearing back. I guess a better whistle can be used safely hardly get - but I would recommend more for large-scale outdoor use; o)
