This Single-Phase Transformer module is a variant of the Fully Protected Single-Phase Transformer, Model 8341-2, that is fitted with two search coils, which allow observation of the magnetic flux waveform in the iron core. One search coil is wound around the center core and the other around an outer leg of the transformer. These coils are brought out to smaller-size banana terminals on the faceplate so they cannot be damaged by misconnection.