The CSTUB-N-FF-900 from Novaris is a RF Surge Protector with Frequency 400 MHz to 3 GHz, Insertion Loss 0.1 dB, Operating Temperature -40 to 85 Degree C, Return Loss 26 dB, Surge Current 50 kA. Tags: Quarter-Wave Shorting Stub (QWS). More details for CSTUB-N-FF-900 can be seen below.