The IS220PDIAH1B is a GE Mark VIe I/O pack. This can be used with a number of different GE terminal boards. The IS220PDIAH1B has been certified for usage in hazardous environments. IS200STCIH8A, IS200STCIH1A, and 2A, IS200TBCIH2C or H4C, IS400STCIH1A or 2A, IS400TBCIH2C, or IS400STCIH8A are some of the terminal boards that can be used with the PDIA I/O.These are usually power distribution boards from the Speedtronic Mark VIe system.