The QDDC-18000-40000-20 from Qualwave is a Dual Directional Coupler with Coupling 10 to 30 dB, Coupling Variation ±0.7 dB, Frequency 18000 to 40000 MHz, Average Power 20 W, Insertion Loss 1.3 to 2.7 dB. Tags: Module with Connectors. More details for QDDC-18000-40000-20 can be seen below.