The QSDC-400-3900-K1-20-N from Qualwave is a Directional Coupler with Frequency 400 to 3900 MHz, Coupling 20±2 dB, Directivity 17 dB, Average Power 100 W, Insertion Loss 0.5 dB. Tags: Module with Connectors. More details for QSDC-400-3900-K1-20-N can be seen below.