This product is designed for trains and ships and delivers deep bass effect. It is also specially suitable for various heavy‑duty trucks, commercial vehicles, construction machinery and special vehicles. Driven by air pressure, it generates high‑decibel warning sound for driving alert and signal notification. Adopting high‑strength metal cavity, it features robust structure, excellent vibration and shock resistance and good sealing performance, adapting to harsh working conditions such as vehicle bumping and drastic temperature changes. Easy to install, it produces loud and clear sound with stable and durable performance to meet vehicle safety warning requirements.