The WLKE4-30-40-60-8000-1 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 30 / 40 MHz, Stopband Frequency Chosen Fco x 1.24 to 8 GHz, 3 dB Cutoff Frequency Choice of 30 to 40 MHz, Insertion Loss 0.9 to 1.4 dB, Rejection 60 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLKE4-30-40-60-8000-1 can be seen below.