The Dual Trumpet Air Horn kit has two tones. The high-pitched and low-pitched sound together create a powerful 150dB sound that cannot be ignored. The improved internal structure produces a deeper and higher pitch, loud enough to reduce the risk of injury and damage to the vehicle due to the improved horn system. The dual trumpet air horn can be used on all DC 12V vehicles, including cars, trucks, vans, RVs, motorcycles, buses, and boats. Please ensure your vehicle is DC 12V; it will not work on DC 24V vehicles. The air horn is made of high-quality chrome-plated zinc alloy (will not rust). The all-copper coil, metal trumpet, and compressor are weatherproof. All kits are designed to serve a long time, ensuring the air horn's durability and long lifespan. It can work in a variety of temperature environments, no matter where you are. The dual trumpet air horn kit is very easy to install, you just need to splice a wire from the positive screw terminal to the power wires of the original horn wire or a horn switch installed on the dashboard, then splice a wire to the ground (negative wire).