Thermwell Products AWS2437 24x21-37 Wind Screen Galvanized rails & varnished wood ends Extends from 21 inch to 37 inch Bright mesh screen wire 24-Inch X 21-Inch - 37-Inch Metal Rail Extension Window Screen Bright, Mesh Screen Wire Extends From 21-Inch To 37-Inch Galvanized Rails, And Varnished Wood Ends Extra Sturdy, Tenoned Corners Keep Screens Square