The DEI9750-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.3 to 21.5 MHz, Bandwidth 200 kHz, Center Frequency 21.4 MHz, Insertion Loss 10 dB, Rejection 60 dB@±150 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DEI9750-21.40MHz can be seen below.