... 4.EX 1 Application 1.1 The hazardous location of explosive gas mixture , Zone1, Zone 21.2 ... pressure, 80~110Kpa 1.7 Defend grade, IP 672.Main features 2.1 Operation standard,GB3836 ... mounted 3 Specification3.1 This type of explosion-proof telephone made of si-aluminium alloy die-casting, ... glue sealing handle, hang pressure by induction fork of non-contact switch, Increased-safety connecting terminal . ...