The TFS1237 from Vectron International is a Band Pass Filter with Frequency 1215 to 1237 MHz / 1237 to 1254 MHz, Insertion Loss 2 to 4 dB, Rejection 25 to 47 dB, Upper Rejection 30 to 47 dB, Lower Rejection 25 to 37 dB. Tags: Surface Mount, RF SAW Filter. More details for TFS1237 can be seen below.