The DEI9939-12.50MHz from Dynamic Engineers is a Band Pass Filter with Frequency 12.4895 to 12.5105 MHz, Center Frequency 12.5 MHz, Insertion Loss 2.5 dB, Rejection 60 dB@±28 kHz of Center Frequency, Ripple 0.5 dB. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DEI9939-12.50MHz can be seen below.