The ZBF8-W3.91-0.57G-2337 from COM-MW is a Waveguide Filter with Frequency 3.625 to 4.2 GHz, Input Power 200 W, Insertion Loss 0.4 to 0.8 dB, Operating Temperature -40 to 70 Degree C, Rejection Frequency 3.55 to 3.6 GHz / 4.3 GHz. Tags: Band Pass. More details for ZBF8-W3.91-0.57G-2337 can be seen below.