The ZF100 from Antenna Technology Communications is a Waveguide Filter with Frequency 3.7 to 4.2 GHz, Insertion Loss 0.5 to 0.95 dB, Rejection 30 to 70 dB, Rejection Frequency 3.5 - 3.65 / 4.25 - 4.4 GHz. Tags: Band Pass. More details for ZF100 can be seen below.