The FN-4038W from Filtronetics is a Low Pass RF Filter with Frequency DC to 7.1 GHz, Stopband Frequency 7.95 to 10.65 GHz, 3 dB Cutoff Frequency 7.1 GHz, Insertion Loss 1.2 dB, Rejection 10 to 20 dBc. Tags: Module with Connector, Surface Mount. More details for FN-4038W can be seen below.