... ageing, long-term working temperature is -55°C~+135°C.door board:Using polyurethane foam with panel overall, exterior level off ... strong, plus box shell, the more enhance the overall effect.Door frame:Using aluminum alloy production, appearance is neat and easy, durable ... inclined rail, when start the door,the wheel can separate door and doorframe.And when close the door , the wheel can press doorframe ...