It is necessary to verify the sound intensity measured in DECIBEL (dB); the sound frequency measured in HERTZ (Hz), the distance between the audible warning device and the operator and the existing environment noise.

Electric Motor Sirens are suitable for short duty cycle and not for continuous operation. They produce a single tone sound that is without doubt very effective but is easily accustomed to and can therefore loose its effectiveness after a short time. A modulated or intermittent tone can be obtained by using an Electronic Modulator.

Detailed below you will find the various advantages:
- low power consumption
- greater sound output with volume adjustment
- varying tones in the sound frequencies (modulated – bi-tone – multi-tone)
- cyclic and pause option
- intermittent sound option
- progressive sound option
- continuous operation
- combined audible/visual signal option

The light emitted through a smooth dome is exactly the same as that emitted by the bulb while the light through a Fresnel lens is amplified.

Without doubt the Xenon flashing type. The xenon discharge has an extremely high peak intensity in a short light up time.

Undoubtedly the LED even if, at the time of purchase, a LED bulb is more expensive than the other traditional types the extra cost involved is quickly compensated due to the reduction in power consumption and the long duration of the bulb, i.e. 100.000 hours.