The TCD-18-4-75+ from Mini Circuits is a Directional Coupler with Frequency 10 MHz to 1 GHz, Coupling 17.34 to 18.25 dB, Directivity 21.19 to 29.1 dB, Power 1 W, Average Power 1 W. Tags: Surface Mount. More details for TCD-18-4-75+ can be seen below.