The WLK7-35-40-40-6000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 35 / 40 MHz, Stopband Frequency Chosen Fco x 1.19 to 6 GHz, 3 dB Cutoff Frequency Choice of 35 to 40 MHz, Insertion Loss 0.9 to 1.4 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK7-35-40-40-6000-20 can be seen below.