The EFP series has a similar modular design to the HDS series but is designed and certified for use in EX hazardous locations such as drilling rigs and oil refineries. CSA C22.2 No. 182.3-1987, CSA C22.2 No. 30-1986, CSA C22.2 No. 60079-0 – 2007, CSA C22.2 No. 60079-1 - 2007, UL 1977 2nd edition, ISA/ANSI 60079-0 -2009, ISA/ANSI 60079-1-2009, UL1203 4th edition, IEC 6007-0, IEC 60079-1