The FN-1801-1W from Filtronetics is a Band Pass Filter with Frequency 148.76 to 148.85 MHz, Bandwidth ±0.045 MHz, Center Frequency 148.8125 MHz, Insertion Loss 5 dB, Ripple 0.75 dB. Tags: Module with Connectors, Drop-In. More details for FN-1801-1W can be seen below.