The WLKE4-45-90-50-8000-1 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 45 / 90 MHz, Stopband Frequency Chosen Fco x 1.15 to 8 GHz, 3 dB Cutoff Frequency Choice of 45 to 90 MHz, Insertion Loss 0.7 to 1.4 dB, Rejection 50 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLKE4-45-90-50-8000-1 can be seen below.