The AM837B1390 from Anatech Electronics is a Band Pass Filter with Frequency 833.75 to 841.25 MHz, Bandwidth 7.5 MHz, Center Frequency 837.5 MHz, Insertion Loss 3 dB, Upper Rejection 25 dB @ 676.4-691.4 MHz. Tags: Ceramic, Surface Mount, Ceramic Filter. More details for AM837B1390 can be seen below.