click here to view the interactive Voyager installation guide. Installation instructions are also copied below. On the bottom of the Voyager 510S Base unit there are 2 ports. One has an icon or picture of a "Handset" and one has the icon of a "Telephone". 1. Unplug the "Handset" from the base of your existing telephone and plug it into the Voyager 510S base unit where it has the icon of the "Handset". The cable will come out the front of the Voyager 510S base unit. 2. Take the short cable that came with the Voyager 510S and plug it into the port on the base of the Voyager 510S where the icon of the "telephone" is. The cable will come out of the back of the Voyager 510S base unit. 3. Plug the other end into the jack where your "Handset" was on your existing telephone. Make sure the AC Power is plugged into the wall and then you can adjust the configuration setting to the clearest setting. Most units work with the configuration from the box.