The WMC-6-18-20dB-S from Werbel Microwave is a Directional Coupler with Frequency 6 to 18 GHz, Coupling 20 dB, Coupling Variation ±1.25 dB, Frequency Sensitivity ±0.30 to ±1 dB, Directivity 12 to 16 dB. Tags: Module with Connectors. More details for WMC-6-18-20dB-S can be seen below.