The DDTO-2/3-40 from Shanghai Huaxiang Computer Communication Engineering is a Dual Directional Coupler with Coupling 40 dB, Coupling Variation 0.5 dB, Frequency 2 to 3 GHz, Average Power 500 W, Insertion Loss 0.4 dB. Tags: Module with Connectors. More details for DDTO-2/3-40 can be seen below.