The QDDC-300-8000-20-20-S from Qualwave is a Dual Directional Coupler with Coupling 20 dB, Coupling Variation ±1 dB, Frequency 300 to 8000 MHz, Average Power 20 W, Insertion Loss 1.1 dB. Tags: Module with Connectors. More details for QDDC-300-8000-20-20-S can be seen below.