The SF3030AO-1237.5MHz-A from Dynamic Engineers is a Band Pass Filter with Frequency 1225.5 to 1249.5 MHz, Center Frequency 1237.5 MHz, Insertion Loss 2.8 to 4 dB, Upper Rejection 40 to 45 dB, Lower Rejection 40 to 52 dB. Tags: Surface Mount, RF SAW Filter. More details for SF3030AO-1237.5MHz-A can be seen below.