The HDL-28-50-40 from MCLI is a Dual Directional Coupler with Coupling 0.1 to 0.25 dB, Frequency 235 to 800 MHz, Average Power 400 W, Insertion Loss 0.25 dB, Directivity 20 dB. Tags: Module with Connectors. More details for HDL-28-50-40 can be seen below.