The QLF-2000-50 from Qualwave is a Low Pass RF Filter with Frequency DC to 2 GHz, Stopband Frequency 2.3 to 4 GHz, Insertion Loss 1 dB, Upper Rejection 50 dB @ 2.3 to 4 GHz, VSWR 1.50:1. Tags: Module with Connector. More details for QLF-2000-50 can be seen below.