The WLK5-700-1000-40-5000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 700 MHz / 1 GHz, Stopband Frequency Chosen Fco x 1.35 to 5 GHz, 3 dB Cutoff Frequency Choice of 700 MHz to 1 GHz, Insertion Loss 0.3 to 0.4 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK5-700-1000-40-5000-20 can be seen below.