Feature: 1. No Power Operating: The portable hand held siren horn is manually operated, requiring no electrical power. This feature makes it highly portable and allows it to provide effective alerts in places without power supply, making it suitable for emergencies and unexpected situations. 2. Adjustable Volume Control: The hand crank siren horn's volume can be adjusted according to the speed of the handle rotation. The faster the handle is turned, the louder the sound produced. Additionally, pressing the trigger opens the blades to emit an even louder noise, providing customizable alert levels to suit different needs. 3. Impressively Loud Alarm Sound: With a sound output reaching up to 120 decibels and a transfer range of up to 1.24 miles, the portable loud manual siren offers clear and penetrating sound, ensuring it achieves optimal alerting effect. This makes it suitable for effectively alerting large areas in urgent scenarios. 4. Robust Construction: Made from aluminium alloy and coated with paint, the emergency safety manual siren is excellent sturdy and resisting to wear. Its rain proof features make it a good choice for long term use in various environmental conditions. 5. Easy Installation And Versatile Application: The hand loud crank horn can be easily mounted onto a rail bracket (bracket not included) for stable usage. It can also be inverted for convenient storage and transport. Widely applicable in factories, homes, schools, oil depots, warehouses, flood control, disaster relief, and both public and industrial situations, it serves as an efficient tool in minimizing casualties and property damage. Specification: Item Type: Hand Crank Siren Horn Effective Range: Diameter ≥ Approx. 2000m / 6561.68ft Sound Level: 120±2dB Sound Frequency: 600±20Hz (Depending on crank speed) Rated Speed: ≥2000 r/min Main Material: Aluminum Alloy Crank Direction: Clockwise Application: Engineering, School, Flood Control, Nature Disasters and Other Emergency Situations. Package List: 1 x Hand Crank Siren Horn 1 Pack x Accessories