The AM881S399 from Anatech Electronics is a Band Pass Filter with Frequency 849 to 874 MHz, Bandwidth 25 MHz, Center Frequency 861.5 MHz, Insertion Loss 2.5 to 3.0 dB, Upper Rejection 30 dB 924-970 MHz. Tags: Surface Mount, RF SAW Filter. More details for AM881S399 can be seen below.