The AT-HPF-75-12 from AT Microwave is a Waveguide Filter with Frequency 75 to 90 GHz, Insertion Loss -2.5 to -1 dB, Operating Temperature -40 to 85 Degree C, Rejection -40 dBc, Rejection Frequency DC to 70 GHz. Tags: High Pass. More details for AT-HPF-75-12 can be seen below.