The BPF-B48 from Mini Circuits is a Band Pass Filter with Frequency 47 to 49 MHz, Bandwidth 2 MHz, Center Frequency 48 MHz, Insertion Loss 2.73 to 2.77 dB, Rejection 20 dB @ 41 and 56 MHz. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for BPF-B48 can be seen below.