The RFDC5M18G20 from RF-Lambda is a Directional Coupler with Frequency 500 MHz to 18 GHz, Coupling 19 to 21.5 dB, Frequency Sensitivity ±0.7 to ±1 dB, Directivity 10 to 14 dB, Average Power 50 W. Tags: Module with Connectors. More details for RFDC5M18G20 can be seen below.