Material: can be Plastic ,Sheet metal,Stainless steel, Alumunium and Zinc Alloy etc. Products Characteristic: Good performance in Wind load resistance, Watertightness & Airtightness, noiseproof, warm-keeping,& heat insulation, Closing & Opening, our products also: a. Fine surface finish b. Convenient assemble c. Reduce costs for production d. Made as your own favorite design