The AT 20 B5 from LEM is a Current Transducer with AC Input Current 20 A, Output Voltage 0 to 5 V, Supply Voltage 7.5 V, Accuracy 0.015, Frequency 0.05 to 0.06 kHz. Tags: Screw Mount, AC Current Transducer. More details for AT 20 B5 can be seen below.