The ZDC-20-3 from Mini Circuits is a Directional Coupler with Frequency 25 to 400 MHz, Coupling 19.97 to 20.28 dB, Directivity 24.37 to 35.76 dB, Power 1 to 4 W, Average Power 1 to 4 W. Tags: Module with Connectors. More details for ZDC-20-3 can be seen below.