The QDDC-0.004-400-K12-40-S from Qualwave is a Dual Directional Coupler with Coupling 40 dB, Coupling Variation ±2 dB, Frequency 4 kHz to 400 MHz, Average Power 120 W, Insertion Loss 0.8 dB. Tags: Module with Connectors. More details for QDDC-0.004-400-K12-40-S can be seen below.