The DDTO-2-40-J from Shanghai Huaxiang Computer Communication Engineering is a Dual Directional Coupler with Coupling 40 dB, Coupling Variation 1 dB, Frequency 800 MHz to 2 GHz, Average Power 500 W, Insertion Loss 0.3 dB. Tags: Module with Connectors. More details for DDTO-2-40-J can be seen below.