The DDTO-600/3000-50 from Shanghai Huaxiang Computer Communication Engineering is a Dual Directional Coupler with Coupling 50 dB, Coupling Variation 1.5 dB, Frequency 600 MHz to 3 GHz, Average Power 400 W, Insertion Loss 0.5 dB. Tags: Module with Connectors. More details for DDTO-600/3000-50 can be seen below.