The IS Sonos sounder beacon has been approved for use in potentially explosive atmospheres for Group I (Mining) and Group II (Above Ground) applications and incorporates a high Ingress Protected IP66 enclosure. The sounder beacon unit incorporates a two stage alarm option and has a total of 32 selectable tones, selectable via a dip switch on the PCB and produces up to 105dB at 1 Meter. A specially designed time saver base enables quick and easy installation of this unit with no extra cabling to be made to the head of the unit.