The DEI9589-1.65MHz 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 @ -500, 2100 KHz. Tags: Crystal Filter, Suspended Substrate Filter. More details for DEI9589-1.65MHz can be seen below.