The AM423S456 from Anatech Electronics is a Band Pass Filter with Frequency 420.85 to 425.15 MHz, Bandwidth 4.29 MHz, Center Frequency 423 MHz, Insertion Loss 3.2 to 3.5 dB, Upper Rejection 47 dB 442-600 MHz. Tags: Surface Mount, RF SAW Filter. More details for AM423S456 can be seen below.