The DEI5538-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.391 to 21.409 MHz, Bandwidth 18 kHz, Center Frequency 21.4 MHz, Insertion Loss 4.5 dB, Rejection 60 dB@±370 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DEI5538-21.40MHz can be seen below.