The DMCF21A004-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.385 to 21.415 MHz, Bandwidth 30 kHz, Center Frequency 21.4 MHz, Insertion Loss 4 dB, Rejection 70 dB@±35.00 kHz to 90 dB@±50 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DMCF21A004-21.40MHz can be seen below.