The L3706 from Mercury Systems is a Low Pass RF Filter with Frequency 40 to 2500 MHz, Stopband Frequency 3700 to 6000 MHz, Insertion Loss 0.2 dB, Rejection 30 dB, Upper Rejection 30 dB @3700 to 6000 MHz. Tags: Module with Connector. More details for L3706 can be seen below.