Plastic Square Plugs for aesthetic or light duty bearing applications.Square Plugs DescriptionUsed on a wide range of furniture and metal tubing applications.Push-in Rib Design allows for easy assembly and a secure fit.Made from Polyethylene plastic.Long Lasting and UV ProtectedSlides easily on most surfaces.BLACK in color.DETERMINING SIZEWe need to know the Outer Diameter of the square tube and the Tube Gauge.Use chart to determine Tube Gauge, while using the wall thickness as your guide for Plastic Square Plugs. Plastic Tube Plug Gauge Chart