A railing system is provided that illustratively includes a first rail and a second rail where the first rail is spaced-apart from the second rail. At least one cable that extends between the spaced-apart first and second rails. The at least one cable includes a stop sleeve disposed about the cable and positioned adjacent an end of the at least one cable. A cable tensioner having a body, a bore disposed through the body, and a stop surface is located adjacent an opening in the cable tensioner. An adapter that includes a body and a bore that extends into the body. The body of the adapter forms a surface located in contact with an underside surface of the top panel of the second rail between the first and second sidewalls of the second rail.