OPEN BOX - Universal Swing Backing (Sling) THIS UNIVERSAL SWING SLING BACKING ARE USED TO SUPPORT THE CUSHION SEATS. IT IS NOT A SEAT ITSELF. This is an after-market universal replacement swing cushion backing (also know as a swing sling). This is the essential piece in many patio swing models that support the cushion seats. Made of durable 600 Denier nylon fabric. Fits patio swings up to 65 inches long. Adjustable straps for added support, easy installation and a universal fit. NOTE - TYPICALLY, YOU WILL NEED TWO SLINGS, ONE FOR EACH SIDE. SLING SWING BACKING GOES OVER THE SEATING AROUND THE BACKSIDE AND RE-ATTACHES TO ITSELF.