The IS-B50LU-C0 from PolyPhaser is a RF Surge Protector with Frequency 1.5 to 700 MHz, Input Power 2000 W, Insertion Loss 0.1 dB, Operating Temperature -45 to 50 Degree C, Surge Current 50 kA. Tags: Gas Discharge Tube. More details for IS-B50LU-C0 can be seen below.