The WLJ4-600-1000-60-5000-100 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 600 MHz / 1 GHz, Stopband Frequency Chosen Fco x 1.95 to 5 GHz, 3 dB Cutoff Frequency Choice of 600 MHz to 1 GHz, Insertion Loss 0.3 to 0.35 dB, Rejection 60 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLJ4-600-1000-60-5000-100 can be seen below.