The DDTO-3-30 from Shanghai Huaxiang Computer Communication Engineering is a Dual Directional Coupler with Coupling 30 dB, Frequency 2 to 4 GHz, Average Power 500 W, Insertion Loss 0.4 dB, Directivity 18 dB. Tags: Module with Connectors. More details for DDTO-3-30 can be seen below.