Perfect as an emergency whistle. We live in earthquake country, so having a small, powerful whistle on each of my family members is a high priority for me.Great idea for ladies who might be bothered by idiots. The wife has a habit of smiling and saying hi to strangers( which is a nice gesture for most of the time). Twice she was harassed by a lone man who responded with vulgar words when she said hi at grocery store parking lots. I figured she could blow this if some punk bothers her again. She stopped greeting strangers unless they r women.