The FMSP1023 from Fairview Microwave is a RF Surge Protector with Frequency 125 MHz to 1 GHz, Input Power 50 to 375 W, Insertion Loss 0.1 dB, Operating Temperature -55 to 50 Degree C, Return Loss 26 dB. Tags: Gas Discharge Tube. More details for FMSP1023 can be seen below.