This is a Westinghouse 100A 480V 3 Pole AB De-Ion Circuit Breaker. EBH Frame 1A1B Aux Switch PN# 2513-931 Mfr Date 3/74 This unit was pulled from a recently deinstalled working rectifier system. The exterior is in very good condition the lugs are good and the switch is tight. Unfortunately we can't test the unit so we are selling it as is.