The WLK9-2000-6000-40-11000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 2 / 6 GHz, Stopband Frequency Chosen Fco x 1.125 to 11 GHz, 3 dB Cutoff Frequency Choice of 2 to 6 GHz, Insertion Loss 0.6 to 0.9 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK9-2000-6000-40-11000-20 can be seen below.