The QSSNFNF0300 from NexTek, LLC. is a RF Surge Protector with Frequency 820 MHz to 2.2 GHz, Input Power 1.2 kW, Insertion Loss 0.05 to 0.1 dB, Operating Temperature -40 to 90 Degree C, Return Loss 23.1 to 32.3 dB. Tags: Quarter-Wave Shorting Stub (QWS). More details for QSSNFNF0300 can be seen below.