Black casing. 3 1/4”overall. Easy to grip high-impact thermoplastic construction with keyring. Extremely loud for personal protection. Generates a tone 100% louder than a standard police or safety whistle. Works in, on or under water. Ideal for sporting events, campers, hikers, hunters, scuba divers, police and firefighters. Adopted by the U.S. military. Hang packaged.