The WLK3-325-400-60-3000-20 from Wainwright Instruments is a Low Pass RF Filter with Frequency DC to 325 / 400 MHz, Stopband Frequency Chosen Fco x 2.7 to 3 GHz, 3 dB Cutoff Frequency Choice of 325 to 400 MHz, Insertion Loss 0.25 to 0.3 dB, Rejection 60 dB. Tags: Module with Connector, Lumped Component Filter, Chebyshev Filter. More details for WLK3-325-400-60-3000-20 can be seen below.