The 229-304B-dB-dBR-2-2-2-2 from Narda-ATM is a Waveguide Coupler with Frequency 3.3 to 4.9 GHz, Coupling 3 dB, 6 dB, 10 dB, 20 dB, 30 dB, Directivity 40 dB. Tags: Multihole Coupler, Broadwall Coupler. More details for 229-304B-dB-dBR-2-2-2-2 can be seen below.