The QDDC-250-1000-K4-40-N from Qualwave is a Dual Directional Coupler with Coupling 40 dB, Coupling Variation ±1 dB, Frequency 250 to 1000 MHz, Average Power 400 W, Insertion Loss 0.2 dB. Tags: Module with Connectors. More details for QDDC-250-1000-K4-40-N can be seen below.