The QSDC-400-3900-K2-39-N from Qualwave is a Directional Coupler with Frequency 400 to 3900 MHz, Coupling 39±1.5 dB, Directivity 18 dB, Average Power 200 W, Insertion Loss 0.3 dB. Tags: Module with Connectors. More details for QSDC-400-3900-K2-39-N can be seen below.