The 1CSX518-20 from Werbel Microwave is a Directional Coupler with Frequency 500 MHz to 18 GHz, Coupling 20 dB, Coupling Variation ±1 dB, Directivity 10 dB, Average Power 7.5 to 30 W. Tags: Module with Connectors. More details for 1CSX518-20 can be seen below.