The AB1542B748 from Anatech Electronics is a Band Pass Filter with Frequency 1.53 to 1.55 GHz, Bandwidth 20 MHz, Center Frequency 1542 MHz, Insertion Loss 2.5 dB, Upper Rejection 45 dB @ 1562 MHz. Tags: Module with Connectors, Cavity Filter. More details for AB1542B748 can be seen below.