[T316 Stainless Steel] This cable railing hardware was made with T316 stainless steel so you don't have to worry about them rusting over time. Because of their material, you can install them both indoors and out. Use with metal or wood posts. Suitable for outdoor or indoor. [Easy To Install] Invisible cable railing kits work by securing one end of a cable wire within the post. This way, no fasteners are visible to the exterior eye. Invisible Receiver with hexagon socket.