During a fire, chemical-related accident, or break-in, sirens use their howling, surging noise to warn of danger. Special multiple-tone sirens offer the capability of setting individual alarm tones. This allows different tones to be assigned to different dangers or notifications. enhancing safety in industrial operations, for instance, by allowing immediate appropriate reaction to an event. If they are also equipped with a flashing lamp, they can also generate an optical signal. Depending on the model, sirens are suitable for flush or surface mounting on floors or walls.