The WLK4-2000-3000-40-10000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 2 / 3 GHz, Stopband Frequency Chosen Fco x 1.53 to 10 GHz, 3 dB Cutoff Frequency Choice of 2 to 3 GHz, Insertion Loss 0.25 to 0.35 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK4-2000-3000-40-10000-20 can be seen below.