The QDDC-0.004-400-K5-50-NS from Qualwave is a Dual Directional Coupler with Coupling 50 dB, Coupling Variation ±1 dB, Frequency 4 kHz to 400 MHz, Average Power 500 W, Insertion Loss 0.4 dB. Tags: Module with Connectors. More details for QDDC-0.004-400-K5-50-NS can be seen below.