The EMA4F1705P20J50D from ECHO Microwave is a Band Pass Filter with Frequency 1.7 to 1.72 GHz, Insertion Loss 5 dB, Rejection 50 dB @ DC to 1645 MHz, Return Loss 15 dB. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for EMA4F1705P20J50D can be seen below.