The EMA4D3750P100D30A from ECHO Microwave is a Band Pass Filter with Frequency 3.7 to 3.8 GHz, Insertion Loss 2 dB, Rejection 30 to 40 dB, Return Loss 10 dB. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for EMA4D3750P100D30A can be seen below.