The DEI9588-1.65MHz from Dynamic Engineers is a Band Pass Filter with Frequency 0.4 to 2.9 MHz, Bandwidth -350 KHz, -2500 KHz, Center Frequency 1.65 MHz, Insertion Loss 3 dB, Rejection 60 dB @ 1500 KHz, - 4000 KHz. Tags: Crystal Filter, Suspended Substrate Filter. More details for DEI9588-1.65MHz can be seen below.