This unit intervenes between I.S. Battery-less Telephones in hazardous areas and telephones in safety areas to establish safety connection. For calling device Relay contact Ratings : AC/DC 6A, Power supply for barrier : DC 24V, max. 0.5A, Ex. Protection : Exia II B Ta=60℃, Please specify the model number as below: Model ODZ9492- ① ② ① Maximum number of telephones possible to equip at hazardous area : 1: equip 1 unit, 2 : equip 2 units, 3 : equip 3 units, 4 : equip 4 units ② Maximum number of telephones possible to equip at safe area in total A : 8 stations, B : 16 stations, C : 24 stations Example) 1 x telephone in hazardous area, 8 telephone system in safe area should be “ODZ9492-1A”