The BSF-920MS1 from RF ONE Electronics is a Band Stop Filter with Stopband Frequency 0.917 to 0.9235 GHz, Insertion Loss 3 dB, Rejection 40 dB, Power 20 W, Return Loss 10 dB. Tags: Module with Connectors, Cavity Filter, Ceramic Filter, LC Filter. More details for BSF-920MS1 can be seen below.