Ultra Heavy Duty Impact traffic doors open easily and close automatically, low maintenance. Applications & Environment: supermarket, retail, food processing, warehouse, industrial, pharmaceutical, postal, hospital, freezer, cooler, logistic system, loading dock and so on. Functions & Parameters: Door Panel: Outer skin is stainless steel or polyethylene; Panel thickness is 20mm or 40mm; Could endure high pressure, moistureproof, airproof, anti-corrosive, environment protection; Durable gasketing is factory applied without use of metal strips or fasterners, making it easy to replace in the field. Upper Hinge: Double acting V-cam hinging system operates smoothly and is virtually maintenance free with its permanently Iubricated needle bearing roller assembly. Bottom Hinge: The bottom hinge attaches to to internal steel reinforcement and is constructed with aluminum hinge shaft for additional strength and durability. Window: Large polycarbonate windows are virtually scratch resistant. Internal Reinforcement: A reinforcement frame is molded in the door and runs the full length of the panel. The frame sets into the panel for structural stability and strength. Easy Spring Bumper: 18" high scuff plate (both sides).