GRP enclosures are used on Hetronic Ex receivers for Zone 2 Gas and Zone 22 Dust classified environments. A Restricted Breathing Safety Concept approach ensures that the possibility of entry of a surrounding explosive Gas/Dust atmosphere which is typically less than 10hrs a year is reduced to a low level. These Ex enclosures can safely accommodate all Ex approved Hetronic receiver boards and intrinsically safe components. They offer connections through Ex approved cable glands and cables.