The WLK3-50-75-40-3000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 50 / 75 MHz, Stopband Frequency Chosen Fco x 2 to 3 GHz, 3 dB Cutoff Frequency Choice of 50 to 75 MHz, Insertion Loss 0.3 to 0.4 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK3-50-75-40-3000-20 can be seen below.