The EMA4D2311P12F33B from ECHO Microwave is a Band Pass Filter with Frequency 2.31 to 2.32 GHz, Insertion Loss 3 dB, Rejection 33 dB @ 2350.4 to 2360 MHz, Return Loss 12 dB. Tags: Surface Mount, Ceramic, Ceramic Filter. More details for EMA4D2311P12F33B can be seen below.