The BSF-723MN4 from RF ONE Electronics is a Band Stop Filter with Stopband Frequency 0.718 to 0.728 GHz, Insertion Loss 3 dB, Rejection 40 dB, Power 100 W, Return Loss 10 dB. Tags: Module with Connectors, Cavity Filter, Ceramic Filter, LC Filter. More details for BSF-723MN4 can be seen below.