The FN-3748W from Filtronetics is a Low Pass RF Filter with Frequency DC to 1120 MHz, Stopband Frequency 1760 MHz, 3 dB Cutoff Frequency 1120 MHz, Insertion Loss 0.5 dB, Rejection 40 dB. Tags: Module with Connector, Surface Mount. More details for FN-3748W can be seen below.
