If you are trying to link several line cords together, or extending existing modular cable runs, Cables To Go's In-RJ45 8-pin Modular Straight-Through Inline Coupler... To link several line cords together, or extend modular cable runs, this modular coupler can help you make the right connection. This inline coupler provides a female-to-female feed-through connection for easy cable hookup. Use for data/PBX applications.