High Frequency Coach, Referee, Outdoor Camping, Hiking, and Rescue Whistle. Though smaller than most whistles it boast impressive sound. -Narrow air chamber with natural cork ball produces high frequency sound. The volume near can reach 129+dB. -Despite the compact size the finger tab allows for easily grasping the whistle either with the thumb and index finger or with 2 fingers without interfering with the sound output. -304 stainless steel and electroplating technology for safety and corrosion resistance. -Small and lightweight, it is convenient to put in your hand or pocket, or attach a neck strap and hang it around your neck. -Ridge on the underside provides grip for lips for hands-free use. -It can be used for sports games and emergencies. Perfect for sports referees, coaches, teachers, lifeguards, leaders, campers, and anyone who might need attention. Available in Assorted Colors.