This screen retainer spline is constructed of top quality vinyl that is round in shape. It features a hollow core center it is serrated on its exterior surface and it is black in color. Vinyl screen retainer spline like this one is used to hold fiberglass and aluminum screen material to screen frames of both windows and doors. This retainer spline has an outside diameter of .185 (3/16 in.) and measures 500 feet in length. Brand Name: Prime-Line Diameter: 0.185 in. Length: 500 ft. Product Type: Screen Spline Packaging Type: Spool Material: Vinyl Color: Black