The DEI9831-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.39 to 21.41 MHz, Bandwidth 20 kHz, Center Frequency 21.4 MHz, Insertion Loss 6 dB, Rejection 70 dB@±100 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DEI9831-21.40MHz can be seen below.