The FN-4184W from Filtronetics is a Low Pass RF Filter with Frequency DC to 3100 MHz, Stopband Frequency 4040 to 7100 MHz, 3 dB Cutoff Frequency 3100 MHz, Insertion Loss 1.5 dB, Rejection 55 to 60 dB. Tags: Module with Connector. More details for FN-4184W can be seen below.