The combination of galvanized side rails and varnished wood ends deliver a sturdy long lasting product The combination of galvanized side rails and varnished wood ends deliver a sturdy long lasting product Comes in 7 inch, 10 inch, 15 inch, 18 inch, 24 inch height and is expandable from 21 - 37, 15 - 25, 19 - 33, 25 - 45 inches in width Bright mesh screen allows for relaxing air circulation while keeping out any spring or seasonal nuisances Save on air condition costs with the use of our adjustable mesh screen and turning off the air condition during the open window seasons.