The DEI3919-1.75MHz from Dynamic Engineers is a Band Pass Filter with Frequency 0.05 to 3.45 MHz, Bandwidth 300 KHz, 3400 kHz, Center Frequency 1.75 MHz, Insertion Loss 6 dB, Rejection 35 dB @-300 to 4500 KHz. Tags: Crystal Filter, Suspended Substrate Filter. More details for DEI3919-1.75MHz can be seen below.