The ZFDC-20-4 (+) from Mini Circuits is a Directional Coupler with Frequency 1 MHz to 1 GHz, Coupling 19.42 to 19.87 dB, Directivity 28.03 to 46.16 dB, Power 0.5 to 2 W, Average Power 0.5 to 2 W. Tags: Module with Connectors. More details for ZFDC-20-4 (+) can be seen below.