The ZFDC-20-4L from Mini Circuits is a Directional Coupler with Frequency 10 MHz to 1 GHz, Coupling 19.57 to 20.21 dB, Directivity 19.77 to 47.4 dB, Power 1 W, Average Power 1 W. Tags: Module with Connectors. More details for ZFDC-20-4L can be seen below.