The AM1227B520 from Anatech Electronics is a Band Pass Filter with Frequency 1.22 to 1.24 GHz, Bandwidth 20 MHz, Center Frequency 1227 MHz, Insertion Loss 1 dB, Upper Rejection 30 dB @ 1302.6 MHz. Tags: Ceramic, Surface Mount, Ceramic Filter. More details for AM1227B520 can be seen below.