The BWLF-20 from Sainty-Tech Communications Limited is a Low Pass RF Filter with Frequency DC to 20 GHz, 3 dB Cutoff Frequency 20 GHz, Insertion Loss 2.0 dB @20GHz, Rejection 20 dB @29.5GHz, 40 dB @37.8GHz, Power 30 dBm. Tags: Die. More details for BWLF-20 can be seen below.