It is a whistle marked by the tag "防犯" and blog articles. It allows to add a tag to a product and a blog article in this site and to display a relevant thing.
Having a whistle increases the probability of survival, so let's possess it. In that case, it is important to be able to produce a distinct loud sound and to blow easily. In order to use it in case of emergency, I will put as many as possible in the life zone.