Q: What material are these Proberos sports whistles made of?A: The whistles are made from premium anti-impact ABS plastic, making them lightweight and highly durable for long-term use.Q: How loud is the whistle and how does it produce sound?A: The whistle produces a crisp, high pitch sound at approximately 120 decibels using dual side air vents, providing excellent audibility both indoors and outdoors without a vibrating core.Q: Are these whistles easy to carry and use?A: Yes, each whistle measures 2.75*2*0.6 cm, includes a metal keychain and comes with an adjustable lanyard for hands-free convenience, making it compact and portable.Q: What accessories are included with the whistle?A: Each pack comes with 2 whistles, a black adjustable lanyard, and a keyring on each whistle for easy attachment to bags, hooks, or keychains.Q: What are the recommended uses for this whistle?A: These professional sports whistles are suitable for referees, coaches, teachers, training, lifeguards, survival, emergency, school, and gym use.