The WLJ3-600-1000-40-5000-100 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 600 MHz / 1 GHz, Stopband Frequency Chosen Fco x 2 to 5 GHz, 3 dB Cutoff Frequency Choice of 600 MHz to 1 GHz, Insertion Loss 0.2 to 0.3 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLJ3-600-1000-40-5000-100 can be seen below.