The FN-4431W from Filtronetics is a Band Pass Filter with Frequency 4.399 to 4.401 MHz, Bandwidth ±0.002 MHz, Center Frequency 4.4 MHz, Insertion Loss 6 dB, Power 1000000 W. Tags: Drop-In, Module with Connectors, Crystal Filter. More details for FN-4431W can be seen below.