The FN-2288W from Filtronetics is a Low Pass RF Filter with Frequency DC to 250 kHz, Stopband Frequency 300 KHz, 3 dB Cutoff Frequency 250 kHz, Insertion Loss 0.5 dB, Rejection 70 dB. Tags: Drop-In, Module with Connector. More details for FN-2288W can be seen below.