The S2501 from Mercury Systems is a Low Pass RF Filter with Frequency 1400 to 2400 MHz, Stopband Frequency 5400 to 5920 MHz, Insertion Loss 0.5 dB, Rejection 80 dB, Upper Rejection 80 dB @ 5400 to 5920 MHz. Tags: Module with Connector. More details for S2501 can be seen below.