Voyeah Set of 3 Aluminum Emergency Survival Whistle with Keychain for Hiking Camping Sports Material: Aluminum. 100 Brand New Keychain for attachment to a lanyard or keys Loud sound. Great for sporting events, camping, hiking or emergencies, survival, disaster preparedness Size: 35mm length, 6mm diameter Package includes: 3 aluminum survival whistle (colors: gold, red, blue)