The WLK10-300-700-40-6000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 300 / 700 MHz, Stopband Frequency Chosen Fco x 1.1 to 6 GHz, 3 dB Cutoff Frequency Choice of 300 to 700 MHz, Insertion Loss 0.8 to 1.3 dB, Rejection 40 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK10-300-700-40-6000-20 can be seen below.