The 20825 3550-4150 from Microwave Filter Company is a Waveguide Filter with Frequency 3.55 to 4.15 GHz, Insertion Loss 0.53 to 0.6 dB, Rejection 45 to 90 dB, Rejection Frequency 3.4 to 4.35 GHz. Tags: Band Pass. More details for 20825 3550-4150 can be seen below.