The DMCF21B003-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.3925 to 21.4075 MHz, Bandwidth 15 kHz, Center Frequency 21.4 MHz, Insertion Loss 3.5 dB, Rejection 70 dB@±17.5 kHz to 90 dB@±25 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DMCF21B003-21.40MHz can be seen below.