The AT-BPF-210230-04 from AT Microwave is a Waveguide Filter with Frequency 210 to 230 GHz, Insertion Loss -3 to -1.8 dB, Operating Temperature -40 to 85 Degree C, Rejection -40 dB, Rejection Frequency 170 to 260 GHz. Tags: Band Pass. More details for AT-BPF-210230-04 can be seen below.