The WLK8-50-65-40-6000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 50 / 65 MHz, Stopband Frequency Chosen Fco x 1.16 to 6 GHz, 3 dB Cutoff Frequency Choice of 50 to 65 MHz, Insertion Loss 0.95 to 1.5 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK8-50-65-40-6000-20 can be seen below.