The DO-12dB-400 from Wuhan Zhongyuan Tiankui Technology Development is a Directional Coupler with Frequency 350 to 480 MHz, Coupling 12 dB, Insertion Loss 0.6 dB, Isolation 20 dB, PIM -120 dBc. Tags: Module with Connectors. More details for DO-12dB-400 can be seen below.