Loud, explosion-proof electromechanical signal horn with a typical bell tone, Certified for use in gas and dust hazardous areas of zone 1, 2, 21, 22, Flame-proof enclosure "d", Terminal connection chamber "increased safety , Housing made of glass-fibre-reinforced plastic, Degree of protection IP 66, max. 105 dB (A) in 1 m, Protection class II, no equipotential bonding required, robust design, Model with integrated telephone-call current relay available