The FN-3337W from Filtronetics is a Low Pass RF Filter with Frequency DC to 822 MHz, Stopband Frequency 906 MHz to 4 GHz, 3 dB Cutoff Frequency 822 MHz, Insertion Loss 0.25 dB, Rejection 40 dB. Tags: Module with Connector. More details for FN-3337W can be seen below.