The DMCF21C001-21.40MHz from Dynamic Engineers is a Band Pass Filter with Frequency 21.39625 to 21.40375 MHz, Bandwidth 7.5 kHz, Center Frequency 21.4 MHz, Insertion Loss 4 dB, Rejection 70 dB@±8.75 kHz to 90 dB@±12.5 kHz of Center Frequency. Tags: Surface Mount, Through Hole, Crystal Filter. More details for DMCF21C001-21.40MHz can be seen below.