The AT-BPF-4254-19 from AT Microwave is a Waveguide Filter with Frequency 42 to 54 GHz, Insertion Loss -2.5 to -1 dB, Operating Temperature -40 to 85 Degree C, Rejection -40 to -30 dB, Rejection Frequency DC to 80 GHz. Tags: Band Pass. More details for AT-BPF-4254-19 can be seen below.