In all working, manufacturing and industrial areas signalling (mainly optical) and alarm systems (mainly acoustic) exist to warn people for any latent, imminent or in progress dangers. Even more so, these systems must be provided in classified areas with danger of explosion to effectively warn everyone of the actual state of looming danger. For these contingencies, and also to set the most basic safety criteria, COELBO has made available to its customers a range of well-articulated “field” signallers, certified in accordance with ATEX Directive, normally triggered by alarm equipment and/or sensors specific to the nature of occurring hazards (presence of fumes, gases and toxic atmospheres, fire, radiations, accidents , malfunctions, etc.).