... resources scheduling,shipping ,shipping port ,railway tunnel and other rough area.2 Feature2.1 Shell of the explosion-proof telephone ... to IP67, good hand feeling,sturdy and durable.2.3 Handle adopts imported Pc engineer material, thermostability of the PTFE ... ,memory,dial (Each number up to 16 )2.7 Easy for install and operate3.Technical parameterDefend gradeIP67Ambient temperature-40~+70°CRelative ...