Model K4-1-EN-H-120 Air Alarm is designed for an area warning radius of up to 6 kilometers. This omni directional horn has durable, solid cast aluminum bell construction and stainless steel diaphragm disc. The K4-1-EN-H-120 includes a self-contained weatherproof air compressor assembly. This eliminates the need for an external air compressor and association piping. Typical applications include: Open pit mine, blasting signal, school, factory warning, pulp and paper mill, refinery warning etc.