The locomotive train air horns used for these kits are constructed from the most durable automotive materials available including heavy duty fiberglass reinforced ABS plastic, stainless steel, and brass. These horns are crafted to meet rigorous standards in the USA. The diaphragms are stainless steel and will never rust!Use this product in a safe and responsible manner, at a distance of at least 100 feet from others.Proper Hearing protection must be worn when using this air horn. Hearing loss or permanent damage may result from unsafe use.Never operate this product in a closed environment or close to pedestrians or others.It is the consumer's responsibility to comply with local noise ordinances and D.O.T. sound level laws.