The DEI5181-12.50MHz from Dynamic Engineers is a Band Pass Filter with Frequency 12.491 to 12.509 MHz, Bandwidth 18 kHz, Center Frequency 12.5 MHz, Insertion Loss 3.5 dB, Rejection 40 dB@±45 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DEI5181-12.50MHz can be seen below.