The ECS-DSF947.5B-21 from ECS Inc. International is a Band Pass Filter with Frequency 935 to 960 MHz, Bandwidth 25 MHz, Center Frequency 947.5 MHz, Insertion Loss 3.3 dB, Rejection 25 to 50 dB. Tags: Surface Mount, RF SAW Filter. More details for ECS-DSF947.5B-21 can be seen below.