The QDDC-4000-5100-K25-40-NS from Qualwave is a Dual Directional Coupler with Coupling 40 dB, Coupling Variation ±0.5 dB, Frequency 4000 to 5100 MHz, Average Power 250 W, Insertion Loss 0.5 dB. Tags: Module with Connectors. More details for QDDC-4000-5100-K25-40-NS can be seen below.