The WLK5-600-700-40-5000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 600 / 700 MHz, Stopband Frequency Chosen Fco x 1.35 to 5 GHz, 3 dB Cutoff Frequency Choice of 600 to 700 MHz, Insertion Loss 0.3 to 0.5 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK5-600-700-40-5000-20 can be seen below.