The WLJ5-1800-1900-40-6000-300 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 1.8 / 1.9 GHz, Stopband Frequency Chosen Fco x 1.53 to 6 GHz, 3 dB Cutoff Frequency Choice of 1.8 to 1.9 GHz, Insertion Loss 0.25 to 0.3 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLJ5-1800-1900-40-6000-300 can be seen below.