คุณลักษณะ

• A name tag with a whistle to let you know where you are in case of a disaster.
• Easy-to-hear sound: Produces a sound of about 3000 Hz, which is the easiest for human ears to hear.
• Blow lightly to produce sound: A typical adult male can produce a loud sound of about 95db. You can make a sound just by blowing lightly, so you can call for help even if you can't speak.