The LC9SR-4000M-50-2A from TTE Filters is a Low Pass RF Filter with Frequency DC to 4 GHz, 3 dB Cutoff Frequency 4 GHz, Insertion Loss 1 dB, Rejection 40 dBc / 60 dBc, Power 10 W. Tags: Module with Connector, Chebyshev Filter. More details for LC9SR-4000M-50-2A can be seen below.