The 21000 3760-4200 from Microwave Filter Company is a Waveguide Filter with Frequency 3.76 to 4.2 GHz, Insertion Loss 0.59 to 1 dB, Rejection 45 to 90 dB, Rejection Frequency 3.48 to 4.38 GHz. Tags: Band Pass. More details for 21000 3760-4200 can be seen below.