The WLK4-3000-6000-60-11000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 3 / 6 GHz, Stopband Frequency Chosen Fco x 1.95 to 11 GHz, 3 dB Cutoff Frequency Choice of 3 to 6 GHz, Insertion Loss 0.25 to 0.35 dB, Rejection 60 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK4-3000-6000-60-11000-20 can be seen below.