The WLJ5-3000-3500-40-12000-300 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 3 / 3.5 GHz, Stopband Frequency Chosen Fco x 1.53 to 12 GHz, 3 dB Cutoff Frequency Choice of 3 to 3.5 GHz, Insertion Loss 0.25 to 0.3 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLJ5-3000-3500-40-12000-300 can be seen below.