The 18925-1 from Microwave Filter Company is a Waveguide Filter with Frequency 3.4 to 4.2 GHz / 4.5 to 4.8 GHz, Insertion Loss 0.2 dB, Rejection 20 to 30 dB, Rejection Frequency 4.25 to 4.40 GHz. Tags: Band Pass. More details for 18925-1 can be seen below.