The QDDC-20-500-K5-50-NS from Qualwave is a Dual Directional Coupler with Coupling 50 dB, Coupling Variation ±1.2 dB, Frequency 20 to 500 MHz, Average Power 500 W, Insertion Loss 0.2 dB. Tags: Module with Connectors. More details for QDDC-20-500-K5-50-NS can be seen below.