The BSF-1843M7 from RF ONE Electronics is a Band Stop Filter with Stopband Frequency 1.805 to 1.88 GHz, Insertion Loss 3 dB, Rejection 40 dB, Power 40 W, Return Loss 9.5 dB. Tags: Module with Connectors, Cavity Filter, Ceramic Filter, LC Filter. More details for BSF-1843M7 can be seen below.