The DMCF21D004-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.394 to 21.406 MHz, Bandwidth 12 kHz, Center Frequency 21.4 MHz, Insertion Loss 2.5 dB, Rejection 40 dB@± 20 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DMCF21D004-21.40MHz can be seen below.