The L54129 from Mercury Systems is a GPS/GNSS Filter Amplifier with Frequency 1.56742 to 1.58342 GHz, Noise Figure 1 to 1.5 dB, Attenuation/Rejection 50 dB, Current 60 mA, Gain 25 dB. Tags: Module with Connector. More details for L54129 can be seen below.